Engine Cooling System Chevrolet Cab & Chassis Silverado 3500

Fastener Tightening Specifications

Fastener Tightening Specifications

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Auxiliary Water Pump (HP2) Connector & Terminal Parts Information

Auxiliary Water Pump (HP2) Terminal Identification

Scheme 8

Coolant Level Switch (8.1L) Connector & Terminal Parts Information

Coolant Level Switch (8.1L) Terminal Identification

Scheme 9

Coolant Level Switch (Diesel) Connector & Terminal Parts Information

Coolant Level Switch (Diesel) Terminal Identification

Scheme 10

Cooling Fan - Left (10 Series) Connector & Terminal Parts Information

Cooling Fan - Left (10 Series) Terminal Identification

Cooling Fan - Right (10 Series)

Cooling Fan - Right (10 Series) Connector & Terminal Parts Information

Cooling Fan - Right (10 Series) Terminal Identification

Starter/Generator Control Module Coolant Pump (HP2)

Starter/Generator Control Module Coolant Pump (HP2) Connector & Terminal Parts Information

Starter/Generator Control Module Coolant Pump (HP2) Terminal Identification

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Engine Cooling

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system.
2. The ability of the control modules to communicate through the serial data circuit.
3. The identification of any stored diagnostic trouble codes DTCs and their status.

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls

PCM - 4.2L, 5.3L

Scan Tool Data List

PCM - 2.4L

Circuit Description

The powertrain control module (PCM) controls the low speed cooling fan operation by grounding the low speed fan relay control circuit with an internal solid state device called a driver. For high speed cooling fan operation, the PCM grounds the high speed and S/P relay control circuit at the same time the low speed control circuit is grounded. Battery positive voltage is supplied to the low speed, high speed, and S/P fan relays. When the PCM is commanding a fan relay ON, the voltage of the control circuit should be low, near 0 volts. When the PCM is commanding a fan relay OFF, the voltage potential of the control circuit should be high, near battery voltage.

The PCM monitors the relay control circuits for the following conditions

1. Short to ground
2. Short to voltage
3. An open circuit

If the PCM detects an improper voltage level on the low or high speed driver circuits, then code P0480 or P0481 will set and the effected driver will be disabled.

1. Cooling fan relay 1 control circuit refers to the low speed cooling fan relay
2. Cooling fan relay 2 control circuit refers to the high speed cooling fan relay

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC P0480 Cooling Fan Relay 1 Control Circuit
2. DTC P0481 Cooling Fan Relay 2 Control Circuit

Conditions for Running the DTC

1. The ignition voltage is between 8-18 volts.
2. The engine speed is more than 40 RPM.
3. The ECM driver transitions from ON to OFF or from OFF to ON.

Conditions for Setting the DTC

1. P0481-The PCM detects an open circuit on the high speed cooling fan relay control circuit.
2. P0480-The PCM detects an open on the low speed cooling fan relay control circuit.
3. The above condition is present for one second.

Action Taken When the DTC Sets

1. The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
2. The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC

1. The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
2. The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. Use the scan tool Clear DTC Information function.

Diagnostic Aids

1. If the condition is not present, refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor) .
2. Review the Freeze Frame/Failure Records vehicle mileage since the diagnostic test failed. This may help determine how often the condition that caused the DTC to be set occurs.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Listen for an audible click when the low speed fan relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
2. 3: Listen for an audible click when the S/P and high speed fan relays operate. Command both the ON and OFF states. Repeat the commands as necessary.

DTC P0480 or P0481

The powertrain control module (PCM) uses the ECT sensor to monitor the engine for an over temperature condition. This condition occurs when the coolant temperature is above 132°C (270°F). When an over temperature condition is present, DTC P1258 will set. The PCM will disable two groups of four cylinders by turning OFF the fuel injectors. By switching between the 2 groups of cylinders, the PCM is able to reduce the temperature of the coolant.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P1258 Engine Coolant Overtemperature - Protection Mode Active

1. DTCs P0117, P0118, P1114, and P1115 are not active.
2. The engine is running.

The engine coolant temperature is above 132°C (270°F) for 10 seconds or more.

1. The PCM will illuminate the malfunction indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
2. The PCM will signal the instrument panel cluster (IPC) to turn ON the Service Engine Soon indicator.
3. The PCM will alternately disable two groups of four cylinders by turning OFF the fuel injectors.
4. The PCM will store conditions which were present when the DTC set as Freeze Frame and File Records data.

1. The PCM will turn the MIL OFF after 3 consecutive trips that the diagnostic has been run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P1258

Symptoms - Engine Cooling

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to «Checking Aftermarket Accessories»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect the surge tank reservoir for the proper coolant level.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Engine Overheated Indicator Always On»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheated-indicator-always-on)
2. «Engine Coolant Temperature Indicator Always On»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-coolant-temperature-indicator-always-on)
3. «Low Engine Coolant Indicator Always On»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
4. «Engine Overheating»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
5. «Loss of Coolant»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
6. «Thermostat Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
7. «Coolant Heater Inoperative (Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Inoperative (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
8. «Engine Fails To Reach Normal Operating Temperature»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)
9. «Fan Clutch Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__fan-clutch-diagnosis)

Engine Overheated Indicator Always On

Engine Overheated Indicator Always On

Engine Coolant Temperature Indicator Always On

Engine Coolant Temperature Indicator Always On

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Low Engine Coolant Indicator Always On

Circuit/System Description

The low engine coolant level indicator lamp is controlled by the engine control module (ECM). The normal state of the engine coolant level switch is closed when in contact with coolant.

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Cooling System Connector End Views

Description and Operation

Cooling System Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Scan Tool Output Controls

Circuit/System Verification

The low coolant indicator should be OFF with the engine coolant at the proper level.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the coolant level switch.
2. Install a 3A fused jumper wire between the signal circuit terminal and ground.
3. Engine running, verify the low coolant indicator turns OFF. If the indicator does not turn OFF, test the signal circuit for an open/high resistance. If the indicator turns OFF, test the ground circuit for an open/high resistance.
4. If all circuits test normal, replace the coolant level switch.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Surge Tank Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Control Module References»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)
3. «Instrument Cluster Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Repair Verification

Verify that the low coolant indicator is OFF with the engine coolant at the proper level.

Cooling Fan Always On

Cooling Fan Always On

The optional coolant heater operates using 110 volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__wiring-repairs)

Test the engine coolant heater cord for an open or short to ground.

1. If open or shorted, replace the coolant heater cord. If the heater tests normal, replace the coolant heater power cord.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Coolant Heater Cord Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Cord Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Overheating

Engine Overheating

Loss of Coolant

Loss of Coolant

Tools Required

J 24731 Tempil Stick. See Special Tools .

Use one of the following procedures in testing for a malfunctioning thermostat.

Thermostat Test Procedure Using Tempil Sticks

The coolant thermostat can be tested using a temperature (tempil) stick. The temperature stick is a pencil like device. It has a wax material containing certain chemicals which melt at a given temperature. Temperature sticks can be used to determine a thermostat's operating range, by rubbing 87°C (188°F) and 97°C (206°F) sticks on the thermostat housing.

1. Use a tempil stick in order to find the opening and the closing temperatures of the coolant thermostat. J 24731 -188 tempil stick melts at 87°C (188°F). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . The thermostat should begin to open. J 24731 -206 tempil stick melts at 97°C (206°F). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . The thermostat should be fully open.
2. Replace the coolant thermostat if it does not operate properly between this temperature range.

Thermostat Test Procedure Using Glycol

Inspect the operation of the thermostat by hanging the thermostat on a hook in a 50/50 percent solution of DEX-COOL® and clean drinkable water.

In order to inspect if the thermostat valve is opening properly, perform the following test

1. Completely submerge the thermostat in the glycol solution. The solution should be 11°C (22°F) above the temperature indicated on the thermostat valve.
2. Thoroughly agitate the solution. Under these conditions, the thermostat valve should open.

In order to inspect if the thermostat valve is closing properly, perform the following test

1. Completely submerge the thermostat in a glycol solution. The solution should be 6°C (10°F) below the temperature indicated on the thermostat valve.
2. Thoroughly agitate the solution. Under these conditions, the thermostat valve should close completely.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The optional coolant heater operates using 110 volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. There is an internal thermal switch in the power cord that prevents operation above -18°C (0°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.

Reference Information

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__wiring-repairs)

1. Test the engine coolant heater for an open or short to ground. If open or shorted, replace the heater.
2. If the heater tests normal, replace the coolant heater power cord.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Coolant Heater Cord Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Cord Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The optional coolant heater operates using 110 volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. There are two heater cords available. One has an internal thermal switch in the power cord that prevents operation above -18°C (0°F) and the other operates at all temperatures. A weather shield on the cord is provided to protect the plug when not in use.

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__wiring-repairs)

1. Test the engine coolant heater for an open or short to ground. If open or shorted, replace the heater.
2. If the heater tests normal, replace the coolant heater power cord.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. «Coolant Heater Cord Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Cord Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)

Engine Fails To Reach Normal Operating Temperature

Engine Fails To Reach Normal Operating Temperature

Pressure Cap Testing

Tools required

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Remove the pressure cap.
2. Wash the pressure cap sealing surface with water.
3. Use the J 24460-01 (1) with J 42401 (2) in order to test the pressure cap. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Maintain the rated pressure for at least 10 seconds. Note the rate of pressure loss.
5. Replace the pressure cap under the following conditions: The pressure cap does not release pressure which exceeds the rated pressure of the cap. The pressure cap does not hold the rated pressure.

Cooling System Leak Testing

Tools Required

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Remove the pressure cap.
2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__pressure-cap-testing) .
3. Wash the pressure cap mating surface with water.
4. Use the J 24460-01 with the. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . J 42401 in order to apply pressure to the cooling system. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Do not exceed the pressure cap rating.
5. The cooling system should hold the rated pressure for at least 2 minutes. Observe the gage for any pressure loss.
6. Repair any leaks as required.

Fan Clutch Diagnosis

Fan Clutch Diagnosis

Draining and Filling Cooling System (Static Fill)

Tools Required

1. J 26568 Coolant and Battery Tester. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 38185 Hose Clamp Pliers. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

Draining Procedure

1. Follow the steps below in order to remove the surge tank fill cap. Slowly rotate the cap counterclockwise. Stop rotating and allow the hissing to stop. After all the hissing stops, continue turning counterclockwise in order to remove the cap.
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
3. Place a drain pan under the lower radiator hose.
4. Using the J 38185 , reposition the lower radiator hose clamp. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
5. Remove the lower radiator hose from the radiator.
6. Drain the cooling system.
7. If a complete engine block drain is required, remove the left and right engine block coolant drain plugs.
8. Remove the engine block coolant heater, if equipped. Refer to «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Inspect the coolant.
10. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Filling Procedure

1. Install the lower radiator hose to the radiator.
2. Using the J 38185 reposition the lower radiator hose clamp. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. If the left and right engine block coolant drain plugs were removed, perform the following. Apply pipe sealer to the drain plugs. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) . Install the drain plugs. Tighten: Tighten the drain plugs to 60 N.m (44 lb ft).
4. Install the engine block coolant heater, if equipped. Refer to «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Lower the vehicle.
6. Open the cooling system bleeder screws, if equipped.
7. Slowly fill the cooling system with a 50/50 coolant mixture. Refer to «Approximate Fluid Capacities»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities) .
8. Close the cooling system bleeder screws, if equipped.
9. Install the coolant pressure cap.
10. Start the engine.
11. Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
12. Allow the engine to idle for 3 minutes.
13. Shut the engine OFF.
14. Allow the engine to cool.
15. Top off the coolant as necessary.
16. Inspect the concentration of the engine coolant using the J 26568 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
17. Rinse away any excess coolant from the engine and the engine compartment.

Draining and Filling Cooling System (w/RPO HP2)

Tools Required

1. J 26568 Coolant and Battery Tester. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. J 38185 Hose Clamp Pliers. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Follow the steps below in order to remove the surge tank fill cap. Slowly rotate the cap counterclockwise. Stop rotating and allow the hissing to stop. After all the hissing stops, continue turning counterclockwise in order to remove the cap.
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
3. Place a drain pan under the lower radiator hose.
4. Using the J 38185 , reposition the lower radiator hose clamp. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
5. Remove the lower radiator hose from the radiator.
6. Drain the cooling system.
7. If a complete engine block drain is required, remove the left and right engine block coolant drain plugs.
8. Remove the engine block coolant heater, if equipped. Refer to «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Inspect the coolant.
10. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

1. Install the lower radiator hose to the radiator.
2. Using the J 38185 reposition the lower radiator hose clamp. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. If the left and right engine block coolant drain plugs were removed, perform the following. Apply pipe sealer to the drain plugs. Install the drain plugs. Tighten: Tighten the drain plugs to 60 N.m (44 lb ft).
4. Install the engine block coolant heater, if equipped. Refer to «Coolant Heater Replacement (4.8L, 5.3L (except RPO L33), 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (5.3L (w/RPO L33))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Coolant Heater Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Lower the vehicle.
6. Open the cooling system bleeder screws, if applicable.
7. Slowly fill the cooling system with a 50/50 coolant mixture. Refer to «Approximate Fluid Capacities»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/lubrication-system/#maintenance-and-lubrication__approximate-fluid-capacities) .
8. Close the cooling system bleeder screws, if applicable.
9. Install the coolant pressure cap.
10. Start the engine.
11. Run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
12. Allow the engine to idle for 3 minutes.
13. Perform the following step 4 times: Run the engine at 4,000 RPM for 30 seconds. Allow the engine to return to idle for 30 seconds.
14. Shut the engine OFF.
15. Allow the engine to cool.
16. Top off the coolant as necessary.
17. Inspect the concentration of the engine coolant using the J 26568 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
18. Rinse away any excess coolant from the engine and the engine compartment.

Draining and Filling Cooling System (Vac-N-Fill)

Tools Required

1. J 26568 Coolant and Battery Tester. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. GE-47716 Vac-N-Fill Coolant Refill Tool
3. J 42401 Radiator Cap and Surge Tank Test Adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .

1. Park the vehicle on a level surface.
2. Remove the coolant pressure cap.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
4. Place a drain pan under the drain cock.
5. Open the radiator drain cock.
6. Drain the cooling system.
7. If a complete engine block drain is required, remove the engine block drain plug.
8. Inspect the coolant.
9. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__flushing) .

Vac-N-Fill Procedure

1. Install the J 42401 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
2. Attach the Van-N-Fill cap to the vehicles coolant fill port.
3. Attach the vacuum gage assembly to the Vac-N-Fill cap.
4. Attach the fill hose to the barb fitting on the vacuum gage assembly. Ensure that the valve is closed.
5. Pour the coolant mixture into the graduated reservoir.
6. Place the fill hose in the graduated reservoir.
7. Install the vacuum tank on the graduated reservoir with the fill hose routed through the cut-out area in the vacuum tank.
8. Attach the venture assembly to the vacuum tank.
9. Attach a shop air hose to the venture assembly. Ensure the valve on the venture assembly is closed.
10. Attach the vacuum hose to the vacuum gage assembly and the vacuum tank.
11. Clamp off the overflow hose.
12. Open the valve on the venture assembly. The vacuum gage will begin to rise and a hissing noise will be present.
13. Continue to draw vacuum until the needle stops rising. This should be 610-660 mm Hg (24-26 in Hg). Cooling hoses may start to collapse. This is normal due to vacuum draw.
14. To aid in the fill process, position the graduated reservoir above the coolant fill port.
15. Slowly open the valve on the vacuum gage assembly. When the coolant reaches the top of the fill hose, close the valve. This will eliminate air from the fill hose.
16. Close the valve on the venture assembly.
17. If there is a suspected leak in the cooling system, allow the system to stabilize under vacuum and monitor for vacuum loss. If vacuum loss is observed, refer to «Loss of Coolant»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
18. Open the valve on the vacuum gage assembly. The vacuum gage will drop as coolant is drawn into the system.
19. Once the vacuum gage reaches zero, close the valve on the vacuum gage assembly and repeat steps 11-17.
20. Remove the J 42401 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
21. Detach the Vac-N-Fill cap from the vehicles coolant fill port.
22. Add coolant to the system as necessary.
23. Inspect the concentration of the coolant mixture using J 26568 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
24. Detach the vacuum hose form the vacuum gage assembly.
25. Attach the extraction hose to the vacuum hose.
26. Open the valve on the venture assembly to start a vacuum draw.
27. Use the extraction hose to draw out coolant to the proper level.
28. The vacuum tank has a drain valve on the bottom of the tank. Open the valve to drain coolant from the vacuum tank into a suitable container for disposal.

Flushing

Radiator Cleaning

Note. The radiator fins are necessary for good heat transfer. Do not brush the fins. This may cause damage to the fins, reducing heat transfer.

1. Some conditions may require the use of warm water and a mild detergent.
2. Clean the A/C condenser fins.
3. Clean between the A/C condenser and radiator.
4. Clean the radiator cooling fins.
5. Straighten any damaged cooling fins.
6. Vehicles equipped with a diesel engine, clean between the charged air cooler and the A/C condenser also. Removal of the charge air cooler may be necessary to clean the fins. Refer to «Charged Air Cooler Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

Removal Procedure

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(ref-277873-S36739584182008012100000) for the 4.3 L engine, «Air Cleaner Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-48l-53l-and-60l-introduction-2-of-2) for the 4.8 L, 5.3 L, and 6.0 L engine or «Air Cleaner Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) for the 8.1 L engine.
3. Remove the surge tank overflow hose from the surge tank.
4. Disconnect the coolant level sensor electrical connector (3).
5. Reposition the surge tank inlet and outlet hose clamps.
6. If equipped with a 4.3 L, 4.8 L, 5.3 L, 6.0 L, or 8.1 L engine, remove the surge tank inlet (1) and outlet (2) hoses from the surge tank.
7. Reposition the surge tank inlet hose clamp from the surge tank.
8. Remove the surge tank inlet hose (1) from the surge tank.
9. Reposition the surge tank outlet hose clamp from the surge tank.
10. Remove the surge tank outlet hose (2) from the surge tank.
11. Remove the bolt from the surge tank.
12. Remove the nut from the surge tank.
13. Remove the surge tank.

Installation Procedure

1. Install the surge tank.
2. Install the bolt to the surge tank. Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. Install the nut to the surge tank. Tighten: Tighten the nut to 9 N.m (80 lb in).
4. Install the surge tank outlet hose (2) to the surge tank.
5. Position the surge tank outlet hose clamp to the surge tank.
6. Install the surge tank inlet hose (1) to the surge tank.
7. Position the surge tank inlet hose clamp to the surge tank.
8. Connect the coolant level sensor electrical connector (3).
9. Install the surge tank overflow hose.
10. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(ref-277873-S36739584182008012100000) for the 4.3 L engine, «Air Cleaner Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-48l-53l-and-60l-introduction-2-of-2) for the 4.8 L, 5.3 L, and 6.0 L engine or «Air Cleaner Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) for the 8.1 L engine.
11. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Reposition the surge tank inlet hose clamp from the radiator.
3. Remove the surge tank inlet hose from the radiator.
4. Reposition the surge tank inlet hose clamp from the surge tank.
5. Remove the surge tank inlet hose (1) from the surge tank.

1. Install the surge tank inlet hose (1) to the surge tank.
2. Position the surge tank inlet hose clamp to the surge tank.
3. Install the surge tank inlet hose to the radiator.
4. Position the surge tank inlet hose clamp to the radiator.
5. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Separate the mass airflow (MAF)/intake air temperature (IAT) sensor assembly and the air inlet tube by loosening the hose clamp.
3. Disconnect the positive crankcase ventilation (PCV) hose from the air cleaner outlet duct.
4. Remove the air inlet tube and resonator retaining wing nut.
5. Remove the air inlet tube and resonator from the throttle body by pivoting the air inlet tube and resonator upward until the hinge clip releases from the lip on the throttle body.
6. Reposition the radiator inlet hose clamp.
7. Remove the radiator inlet hose from the radiator.
8. Reposition the radiator inlet hose clamp at the thermostat housing.
9. Remove the radiator inlet hose from the thermostat housing.
10. Remove the radiator inlet hose.

1. Install the radiator inlet hose to the radiator.
2. Reposition the radiator inlet hose clamp at the radiator.
3. Install the radiator inlet hose to the thermostat housing.
4. Reposition the radiator inlet hose clamp at the thermostat housing.
5. Place the radiator inlet hose onto the support.
6. Align the hinge clip with the lip on the throttle body. Install the air inlet tube and resonator to the throttle body by pivoting the air inlet tube and resonator downward until the mounting stud is through the hole in the air inlet tube.
7. Install the resonator retaining wing nut.
8. Connect the PCV hose to the air cleaner outlet duct.
9. Install the MAF/IAT sensor assembly and the air inlet duct. Tighten: Tighten the clamps to 4 N.m (35 lb in).
10. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet hose.
4. Remove the air cleaner outlet duct.
5. If necessary, remove the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Upper Intake Manifold Sight Shield Replacement (6.0L (RPO LQ9))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
6. Remove the radiator vent inlet hose from the radiator inlet hose clips.
7. Reposition the inlet hose clamp at the radiator.
8. Remove the inlet hose clip from the fan shroud.
9. Remove the inlet hose (1) from the radiator.
10. Reposition the inlet hose clamp at the water pump.
11. Remove the inlet hose from the water pump.

1. Install the inlet hose to the water pump.
2. Position the inlet hose clamp at the water pump.
3. Install the inlet hose (1) to the radiator.
4. Position the inlet hose clamp at the radiator.
5. Install the inlet hose clip to the fan shroud.
6. Install the radiator vent inlet hose to the radiator inlet hose clips.
7. If necessary, install the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Upper Intake Manifold Sight Shield Replacement (6.0L (RPO LQ9))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
8. Install the air cleaner outlet duct.
9. Install the radiator inlet hose clip to the outlet duct.
10. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten: Tighten the clamps to 4 N.m (35 lb in).
11. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet hose.
4. Remove the air cleaner outlet duct.
5. If necessary, remove the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Upper Intake Manifold Sight Shield Replacement (6.0L (RPO LQ9))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
6. Remove the radiator vent inlet hose from the radiator inlet hose clips.
7. Reposition the inlet hose clamp at the radiator.
8. Remove the inlet hose clip from the fan shroud.
9. Remove the inlet hose from the radiator.
10. Reposition the inlet hose clamp at the water pump.
11. Remove the inlet hose from the water pump.

1. Install the inlet hose to the water pump.
2. Position the inlet hose clamp at the water pump.
3. Install the inlet hose to the radiator.
4. Position the inlet hose clamp at the radiator.
5. Install the inlet hose clip to the fan shroud.
6. Install the radiator vent inlet hose to the radiator inlet hose clips.
7. If necessary, install the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Upper Intake Manifold Sight Shield Replacement (6.0L (RPO LQ9))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
8. Install the air cleaner outlet duct.
9. Install the radiator inlet hose clip to the outlet duct.
10. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten: Tighten the clamps to 6 N.m (35 lb in).
11. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the engine coolant. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Move the hose clamps back on the radiator inlet hose.
3. Remove the radiator inlet hose from the radiator.
4. Remove the radiator inlet hose from the water outlet tube.

1. Install the radiator inlet hose to the water outlet tube.
2. Install the radiator inlet hose to the radiator.
3. Install the hose clamps on the radiator outlet hose.
4. Fill the engine coolant. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Reposition the inlet hose clamp at the radiator.
3. Remove the inlet hose from the radiator.
4. Reposition the inlet hose clamp at the water crossover.
5. Remove the inlet hose from the water crossover.

1. Install the inlet hose to the water crossover.
2. Position the inlet hose clamp at the water crossover.
3. Install the inlet hose to the radiator.
4. Position the inlet hose clamp at the radiator.
5. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Separate the mass airflow (MAF)/intake air temperature (IAT) sensor assembly and the air inlet tube by loosening the hose clamp.
2. Disconnect the positive crankcase ventilation (PCV) hose from the air cleaner outlet duct.
3. Remove the air inlet tube and resonator retaining wing nut.
4. Remove the air inlet tube and resonator from the throttle body by pivoting the air inlet tube and resonator upward until the hinge clip releases from the lip on the throttle body.
5. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
6. Reposition the radiator outlet hose clamps at the surge tank and water pump.
7. Remove the radiator outlet hose from the surge tank.
8. Remove the radiator outlet hose from the water pump.
9. Reposition the radiator outlet hose clamp at the radiator.
10. Remove the radiator outlet hose from the radiator.
11. Remove the radiator outlet hose.

1. Install the radiator outlet hose to the radiator.
2. Reposition the radiator outlet hose clamp at the radiator.
3. Install the radiator outlet hose to the water pump.
4. Install the radiator outlet hose to the surge tank.
5. Reposition the radiator outlet hose clamps at the surge tank and water pump.
6. Align the hinge clip with the lip on the throttle body. Install the air inlet tube and resonator to the throttle body by pivoting the air inlet tube and resonator downward until the mounting stud is through the hole in the air inlet tube.
7. Install the resonator retaining wing nut.
8. Connect the PCV hose to the air cleaner outlet duct.
9. Install the MAF/IAT sensor assembly and the air inlet duct. Tighten: Tighten the clamps to 4 N.m (35 lb in).
10. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet duct.
4. Remove the air cleaner outlet duct.
5. Reposition the outlet hose clamp at the water pump.
6. Remove the outlet hose from the water pump.
7. Reposition the outlet hose clamp at the radiator.
8. Remove the outlet hose (6) from the radiator.

1. Install the outlet hose (6) to the radiator.
2. Position the outlet hose clamp at the radiator.
3. Install the outlet hose to the water pump.
4. Position the outlet hose clamp at the water pump.
5. Install the air cleaner outlet duct.
6. Install the radiator inlet hose clip to the outlet duct.
7. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten: Tighten the clamps to 4 N.m (35 lb in).
8. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass air flow (MAF)/intake air temperature (IAT) sensor
3. Remove the radiator inlet hose clip from the outlet duct.
4. Remove the air cleaner outlet duct.
5. Reposition the outlet hose clamp from the water pump.
6. Remove the outlet hose from the water pump.
7. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
8. Remove the bolts from the engine shield.
9. Remove the engine shield from the vehicle.
10. Reposition the radiator outlet hose clamp (2) from the starter/generator stator cooler inlet pipe (3).
11. Remove the radiator outlet hose (1) from the starter/generator stator cooler inlet pipe (3).
12. Reposition the outlet hose clamp from the radiator.
13. Remove the outlet hose from the radiator.

1. Install the outlet hose to the radiator.
2. Position the outlet hose clamp to the radiator.
3. Install the radiator outlet hose (1) to the starter/generator stator cooler inlet pipe (3).
4. Position the radiator outlet hose clamp (2) to the starter/generator stator cooler inlet pipe (3).
5. Install the engine shield to the vehicle.
6. Install the bolts to the engine shield. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
7. Lower the vehicle.
8. Install the outlet hose to the water pump.
9. Position the outlet hose clamp to the water pump.
10. Install the air cleaner outlet duct.
11. Install the radiator inlet hose clip to the outlet duct.
12. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten: Tighten the clamps to 4 N.m (35 lb in).
13. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the engine coolant. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the upper and lower fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) and «Engine Coolant Fan Lower Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the surge tank outlet hose (2) from the surge tank.
4. Remove the radiator outlet hose from the water pump.
5. Remove the heater outlet hose from the radiator outlet hose.
6. Remove the radiator outlet hose from the radiator.
7. Remove the radiator outlet hose clip retainers from the brackets.
8. Remove the radiator outlet hose from the vehicle.

1. Install the radiator outlet hose to the vehicle.
2. Install the radiator outlet hose and clamp to the radiator. Ensure the hose is positioned properly in order to prevent interference with the fan shroud.
3. Install the radiator outlet hose clip retainers to the brackets.
4. Install the surge tank outlet hose (2) to the surge tank.
5. Install the radiator outlet hose and clamp to the water pump.
6. Install the heater outlet hose to the radiator outlet hose.
7. Install the upper and lower fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) and «Engine Coolant Fan Lower Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Fill the engine coolant. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

J 43181 Heater Line Quick Connect Release Tool. See Special Tools .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the radiator outlet hose from the radiator. Refer to «Radiator Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Using the J 43181 disconnect the heater hoses from the heater core outlet. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Install the J 43181 to the heater core pipe. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Close the tool around the heater core pipe. Firmly pull the tool into the quick connect end of the heater hose. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the hose from the heater core.
4. Reposition the surge tank outlet hose clamp at the surge tank.
5. Remove the surge tank outlet hose (2) from the surge tank.
6. Reposition the outlet hose clamp the water pump.
7. Remove the outlet hose from the water pump.

1. Install the outlet hose to the water pump.
2. Position the outlet hose clamp to the water pump.
3. Install the surge tank outlet hose (2) from the surge tank.
4. Position the surge tank outlet hose clamp to the surge tank.
5. Connect the heater and surge tank hoses to the heater core. Firmly push the quick connect onto the heater core pipe until you hear an audible click.
6. Install the radiator outlet hose to the radiator. Refer to «Radiator Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Using a bent-tip screwdriver or equivalent, pull on one of the open ends of the retaining ring in order to rotate the retaining ring.
2. Rotate the retaining ring (3) around the quick connector until the retaining ring is out of position and can be completely removed.
3. Remove the radiator outlet hose (2) from the quick connector fitting at the radiator (1).

1. Hook one of the open ends of the retaining ring (3) in one of the slots in the quick connector.
2. Rotate the retaining ring (3) around the connector until the retaining ring is positioned with all 3 ears through the 3 slots.
3. Ensure the 3 retaining ring ears can be seen from the inside of the connector and the retaining ring can move freely in the slots.
4. Install the radiator outlet hose (2) onto the radiator quick connector fitting until a click is heard or felt. Pull back on the radiator outlet hose (2) to ensure a proper connection.

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Reposition the vent inlet hose clamp from the radiator.
3. Remove the vent inlet hose from the radiator.
4. Reposition the vent inlet hose clamp from the surge tank.
5. Remove the vent inlet hose from the surge tank.

1. Install the vent inlet hose to the surge tank.
2. Reposition the vent inlet hose clamp to the surge tank.
3. Install the vent inlet hose to the radiator.
4. Reposition the vent inlet hose clamp to the radiator.
5. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Disengage the plastic caps from the quick connect fittings. Pull the caps back along the pipe.
2. Using a bent-tip screwdriver or equivalent, pull on one of the open ends of the retaining ring in order to rotate the retaining ring.
3. Rotate the retaining ring around the quick connector until the retaining ring is out of position and can be completely removed. Discard the retaining rings.
4. Remove the engine oil cooler line from the quick connector fitting at the radiator. Pull the lines straight out from the connectors.
5. Clean all of the components in a suitable solvent, and dry them with compressed air.
6. Inspect the fittings, the connectors, the cooler lines, and the cooler for damage, distortion, or restriction. Replace parts as necessary.

1. Install a new retaining ring into each quick connector fitting.
2. Hook one of the open ends of the retaining ring in one of the slots in the quick connector.
3. Rotate the retaining ring around the connector until the retaining ring is positioned with all 3 ears through the 3 slots.
4. Ensure the 3 retaining ring ears can be seen from the inside of the connector and the retaining ring can move freely in the slots.
5. Install the engine oil cooler line into the quick connector fitting until a click is heard or felt. Pull back on the engine oil cooler lines to ensure a proper connection.
6. Snap the plastic cap onto the quick connect fitting.
7. Ensure that the plastic cap is fully seated against the fitting.
8. Ensure that no gap is present between the cap and the fitting.
9. Inspect and fill the engine oil to the proper level.

The optional oil cooler is either an integral part of the radiator or a separate unit placed in front of the radiator. The cooler lines and hoses are serviceable.

1. Disconnect the engine oil cooler quick connect fittings. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. If equipped with a 5.3L or 6.0L engine, perform the following: Open the oil cooler hose clip located on the lower fan shroud. Remove the oil cooler hoses from the clip.
3. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
4. If equipped with a 8.1L engine, perform the following
5. Remove the oil cooler hoses from the clip.
6. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
7. If equipped, remove the engine shield bolts.
8. Remove the engine shield.
9. If equipped with a 5.3L or 6.0L engine, perform the following: Remove the oil cooler hose bracket bolt (1). Remove the oil cooler hose adapter bolts (2). Remove the oil cooler hose assembly and gasket. Discard the gasket. Inspect the fittings, connectors and cooler hoses for damage or distortion.
10. If equipped with a 8.1L engine, perform the following: Remove the oil cooler hose bracket bolt. Disconnect the quick connect fittings (1) at the engine. Remove the oil cooler hose assembly. Discard the gasket. Inspect the fittings, connectors and cooler hoses for damage or distortion.

1. If equipped with a 8.1L engine, perform the following: Install the oil cooler hose assembly and a NEW gasket. Connect the quick connect fittings (1) at the engine. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) . Install the oil cooler hose bracket bolt. Tighten: Tighten the bolt to 50 N.m (37 lb ft).
2. If equipped with a 5.3L or 6.0L engine, perform the following: Install the oil cooler hose assembly and a NEW gasket. Install the oil cooler hose adapter bolts (2). Tighten: Tighten the bolts to 12 N.m (106 lb in). Install the oil cooler hose bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
3. If equipped, install the engine shield.
4. Install the engine shield bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
5. Lower the vehicle.
6. If equipped with a 5.3L or 6.0L engine, perform the following: Install the oil cooler hoses to the hose clip on the fan shroud. Snap the oil cooler hose clip shut.
7. If equipped with a 8.1L engine perform the following
8. Install the oil cooler hoses to the clip.
9. Connect the engine oil cooler quick connect fittings. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

The optional oil cooler is either an integral part of the radiator or a separate unit placed in front of the radiator. The cooler lines and hoses are serviceable.

1. Disconnect the engine oil cooler quick connect fittings. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. If equipped with a 5.3L or 6.0L engine, perform the following: Open the oil cooler hose clip located on the lower fan shroud. Remove the oil cooler hoses from the clip.
3. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
4. If equipped with a 8.1L engine, perform the following
5. Remove the oil cooler hoses from the clip.
6. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
7. Place jack or utility stands at the rear of the vehicle.
8. If equipped, remove the engine protection shield. Refer to «Engine Protection Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
9. If equipped, remove the front differential carrier shield. Refer to «Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/differentials-drive-axles/#front-drive-axle) .
10. Place an adjustable jack under the front differential carrier.
11. Remove the inner axle housing nuts and washers from the bracket.
12. Remove the differential carrier upper mounting bolt and nut.
13. Pivot the differential carrier forward and down on the lower mount bolt while it is being supported by the adjustable jack.
14. Secure the differential carrier to the jack.
15. Remove the differential carrier lower mounting bolt and nut.
16. Lower the jack 4 to 6 inches.
17. If equipped with a 5.3L or 6.0L engine, perform the following: Remove the oil cooler hose bracket bolt (1). Remove the oil cooler hose adapter bolts (2). Remove the oil cooler hose assembly and gasket. Discard the gasket. Inspect the fittings, connectors and cooler hoses for damage or distortion.
18. If equipped with a 8.1L engine, perform the following: Remove the oil cooler hose bracket bolt. Disconnect the quick connect fittings (1) at the engine. Remove the oil cooler hose assembly. Discard the gasket. Inspect the fittings, connectors and cooler hoses for damage or distortion.

1. If equipped with a 8.1L engine, perform the following: Install the oil cooler hose assembly and a NEW gasket. Connect the quick connect fittings (1) at the engine. Install the oil cooler hose bracket bolt. Tighten: Tighten the bolt to 50 N.m (37 lb ft).
2. If equipped with a 5.3L or 6.0L engine, perform the following: Install the oil cooler hose assembly and a NEW gasket. Install the oil cooler hose adapter bolts (2). Tighten: Tighten the bolts to 12 N.m (106 lb in). Install the oil cooler hose bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
3. Raise the jack in order to position the differential carrier.
4. Install the differential carrier lower mounting bolt and nut. Do not tighten the bolt at this time.
5. Pivot the differential carrier up and back on the lower mount bolt while it is being supported by the jack.
6. Install the differential carrier upper mounting bolt and nut. Do not tighten the bolt at this time.
7. Install the inner axle housing washers and nuts to the brackets. Tighten: The inner axle housing bolts to 100 N.m (75 lb ft). The upper and lower differential carrier bolts to 100 N.m (75 lb ft).
8. Remove the adjustable jack from under the front differential carrier.
9. If equipped, install the front differential carrier shield. Refer to «Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/differentials-drive-axles/#front-drive-axle) .
10. If equipped, install the engine protection shield. Refer to «Engine Protection Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
11. Remove the jack or utility stands from the rear of the vehicle.
12. Lower the vehicle.
13. If equipped with a 8.1L engine perform the following
14. Install the oil cooler hoses to the clip.
15. If equipped with a 5.3L or 6.0L engine, perform the following: Install the oil cooler hoses to the hose clip on the fan shroud. Snap the oil cooler hose clip shut.
16. Connect the engine oil cooler quick connect fittings. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

J 41240-5A Fan Clutch Wrench

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the 3 engine cooling fan shroud bolts (1).
3. Position the engine cooling fan shroud (1) forward to the radiator.
4. Install a long pin bar into the fan hub (1).
5. Use a J 41240-5A to remove the fan hub nut (2) from the hub in a counterclockwise rotation.
6. Remove the fan and the engine cooling fan shroud as an assembly.
7. Remove the fan clutch bolts from the rear of the fan blade.
8. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan and engine cooling fan shroud assembly to the fan hub.
4. Use a J 41240-5A on the fan clutch hub nut (2) to install a long pry bar to the fan clutch hub (1). Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Position the engine cooling fan shroud on the 3 mounting brackets (1).
6. Install the bolts. Loosely tighten the top mounting bolt at the oil filler neck.
7. Center the engine cooling fan shroud to the fan blade in 3 places (1).
8. Fully tighten the 3 engine cooling fan shroud bolts (1). Tighten: Tighten the bolts to 8 N.m (71 lb in).
9. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

J 46406 Fan Clutch Remover and Installer. See Special Tools .

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Install the J 46406 to the fan clutch. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. Remove the fan hub nut from the water pump in a counterclockwise rotation.
4. Remove the fan clutch bolts from the rear of the fan blade.
5. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan assembly.
4. Install the J 46406 to the fan clutch. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

J 41240-5A Fan Clutch Wrench

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the 3 engine cooling fan shroud bolts (1).
3. Position the engine cooling fan shroud (1) forward to the radiator.
4. Install a long pin bar into the fan hub (1).
5. Use a J 41240-5A to remove the fan hub nut (2) from the hub in a counterclockwise rotation.
6. Remove the fan and the engine cooling fan shroud as an assembly.
7. Remove the fan clutch bolts from the rear of the fan blade.
8. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts. Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan and engine cooling fan shroud assembly to the fan hub.
4. Use a J 41240-5A on the fan clutch hub nut (2) to install a long pry bar to the fan clutch hub (1). Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Position the engine cooling fan shroud on the 3 mounting brackets (1).
6. Install the bolts. Loosely tighten the top mounting bolt at the oil filler neck.
7. Center the engine cooling fan shroud to the fan blade in 3 places (1).
8. Fully tighten the 3 engine cooling fan shroud bolts (1). Tighten: Tighten the bolts to 8 N.m (71 lb in).
9. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

J 46406 Fan Clutch Remover and Installer. See Special Tools .

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Install the J 46406 to the fan clutch. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
3. Remove the fan hub nut from the water pump in a counterclockwise rotation.
4. Remove the fan clutch bolts from the rear of the fan blade.
5. Separate the fan clutch from the fan blade.

1. Install the fan clutch bolts from the rear of the fan blade.
2. Install the fan clutch bolts. Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan assembly.
4. Install the J 46406 to the fan clutch. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Clutch Replacement (Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Disconnect the camshaft position (CMP) sensor electrical connector.
3. Remove the fan pulley bolts/nuts.
4. Remove the fan pulley.

1. Install the fan pulley.
2. Install the fan pulley bolts/nuts. Tighten: Tighten the bolts/nuts to 41 N.m (30 lb ft).
3. Connect the CMP sensor electrical connector (1).
4. Install the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Clutch Replacement (Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the cooling fan blade retainers.
3. Remove the cooling fan blades.

1. Install the cooling fan blades.
2. Install the cooling fan blade retainers.
3. Install the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the cooling blade(s). Refer to «Engine Cooling Fan Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the cooling fan motor bolts.
3. Remove the cooling fan motor(s).

1. Install the cooling fan motor(s).
2. Install the cooling fan motor bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
3. Install the cooling fan blade(s). Refer to «Engine Cooling Fan Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Disengage the radiator inlet hose clip (2) at the fan shroud.
2. Reposition the surge tank inlet hose clamp at the radiator.
3. Remove the surge tank inlet hose from the radiator.
4. Disconnect the electrical connectors from the cooling fans.
5. Remove the clip attaching the wiring harness to the shroud.
6. If necessary, open the engine oil cooler line clip and remove the cooler lines from the clip.
7. Remove the cooling fan shroud bolts.
8. Remove the cooling fan and shroud.

1. Install the cooling fan and shroud.
2. Install the cooling fan shroud bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
3. If equipped, install the cooler lines to the clip and close the clip.
4. Connect the electrical connectors to the cooling fans.
5. Install the clip attaching the wiring harness to the shroud.
6. Install the surge tank inlet hose to the radiator.
7. Reposition the surge tank inlet hose clamp at the radiator.
8. Engage the radiator inlet hose clip (2) at the fan shroud.

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. Reposition the coolant inlet hose clamp.
4. Disconnect the turbocharger coolant inlet hose from the turbocharger bypass valve.
5. Remove the turbocharger bypass valve and washer.

1. Install the turbocharger bypass valve and washer. Tighten: Tighten the valve to 60 N.m (44 lb ft).
2. Connect the turbocharger coolant inlet hose to the turbocharger bypass valve.
3. Position the coolant inlet hose clamp.
4. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
5. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. Loosen the charged air cooler inlet duct connector to turbocharger clamp (1).
4. Remove the charged air cooler inlet duct connector (4) from the turbocharger.
5. Reposition the turbocharger coolant inlet hose clamp at the bypass valve.
6. Remove the turbocharger coolant inlet hose banjo bolt (1).
7. Remove the inlet hose washer and inlet line.

1. Install the inlet hose washer and inlet line.
2. Install the turbocharger coolant inlet hose banjo bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
3. Position the turbocharger coolant inlet hose clamp at the bypass valve.
4. Remove the tape from the turbocharger openings.
5. Install the charged air cooler inlet duct connector (4) to the turbocharger.
6. Tighten the charged air cooler inlet duct connector to turbocharger clamp (1). Tighten: Tighten the clamp to 6 N.m (53 lb in).
7. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
8. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. Disconnect the negative battery cables. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(ref-277871-S00762267862008012100000) .
5. Using a pick or a small flat-bladed screw driver, remove and discard the quick connect fitting clip from the charged air cooler outlet duct.
6. Remove the charged air cooler duct from the intake.
7. Remove the generator mounting bracket. Refer to «Generator Bracket Replacement (4.3L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Bracket Replacement (4.8L, 5.3L, and 6.0L Engines)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Bracket Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Bracket Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
8. Remove the exhaust gas recirculation (EGR) cooler tube. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(ref-277871-S20280986472008012100000) .
9. Reposition the hose clamp at the bypass pipe.
10. Remove the turbocharger coolant outlet hose from the bypass pipe.
11. Reposition the turbocharger coolant outlet hose clamp.
12. Remove the turbocharger coolant outlet hose from the pipe on the turbocharger.
13. Remove the turbocharger coolant outlet pipe bolt and nut.
14. If necessary, remove the turbocharger. Refer to «Turbocharger Replacement (RPOs LBZ/LLY)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
15. If necessary, remove the coolant outlet pipe clip bolt (3) from the turbocharger.
16. If necessary, remove the coolant outlet pipe.

1. If necessary, install the coolant outlet pipe.
2. If necessary, install the coolant outlet pipe clip bolt (3) to the turbocharger. Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. If necessary, install the turbocharger. Refer to «Turbocharger Replacement (RPOs LBZ/LLY)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
4. Install the turbocharger coolant outlet pipe bolt and nut. Tighten: Tighten the bolt/nut to 9 N.m (80 lb in).
5. Install the turbocharger coolant outlet hose to the pipe on the turbocharger.
6. Position the turbocharger coolant outlet hose clamp.
7. Install the turbocharger coolant outlet hose to the bypass pipe.
8. Position the hose clamp at the bypass pipe.
9. Install the EGR cooler tube. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(ref-277871-S20280986472008012100000) .
10. Install the generator mounting bracket. Refer to «Generator Bracket Replacement (4.3L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Bracket Replacement (4.8L, 5.3L, and 6.0L Engines)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Bracket Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Bracket Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
11. Install a NEW quick connect fitting clip to the charged air cooler duct.
12. Install the charged air cooler duct to the intake.
13. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(ref-277871-S00762267862008012100000) .
14. Connect the negative battery cables. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
15. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
16. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(ref-277871-S00762267862008012100000) .
3. Using a pick or a small flat-bladed screw driver, remove and discard the quick connect fitting clip from the charged air cooler outlet duct.
4. Remove the charged air cooler outlet duct from the intake.
5. Remove the electrical harness bolts.
6. Reposition the engine harness from the air inlet tube.
7. Remove the air inlet tube to intake manifold tube bolt and nut.
8. Disconnect the air intake heater electrical connector.
9. Disconnect manifold absolute pressure (MAP) sensor electrical connector.
10. Remove the engine harness clip from the air inlet tube.
11. Remove the air inlet tube nuts.
12. Remove the air inlet tube.
13. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
14. Reposition the exhaust gas recirculation (EGR) coolant pipe hose clamp.
15. Remove the EGR coolant pipe hose.
16. Remove the EGR coolant pipe bolts.
17. Remove the EGR coolant pipe.
18. Remove and discard the coolant pipe O-ring seal.

1. Install a NEW O-ring seal onto the coolant pipe. Lubricate the seal with engine coolant.
2. Install the EGR coolant pipe.
3. Install the EGR coolant pipe bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
4. Install the EGR coolant pipe hose.
5. Position the EGR coolant pipe hose clamp.
6. Connect the ECT sensor electrical connector.
7. Install the air inlet tube.
8. Install the air inlet tube nuts. Tighten: Tighten the nuts to 25 N.m (18 lb ft).
9. Connect the air intake heater electrical connector.
10. Connect MAP sensor electrical connector.
11. Install the engine harness clip to the air inlet tube.
12. Install the air inlet tube to intake manifold tube bolt and nut. Tighten: Tighten the bolt/nut to 10 N.m (89 lb in).
13. Position the engine harness to the air inlet tube.
14. Install the engine harness bolts. Tighten: Tighten the bolts to 4 N.m (35 lb in).
15. Install a NEW quick connect fitting clip to the charged air cooler duct.
16. Install the charged air cooler outlet duct to the intake.
17. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(ref-277871-S00762267862008012100000) .
18. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
2. Drain the cooling system and engine block. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. If necessary, disconnect the crankshaft position (CKP) sensor electrical connector.
4. Remove the thermal bypass hose bolt.
5. Reposition the thermal bypass hose clamp.
6. Remove the thermal bypass hose from the fitting.
7. Remove the thermal bypass fitting.

Note. Refer to Fastener Notice .

1. Install the thermal bypass fitting. Tighten: Tighten the fitting to 35 N.m (26 lb ft).
2. Install the thermal bypass hose to the fitting.
3. Position the thermal bypass hose clamp.
4. Install the thermal bypass hose bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
5. If necessary, connect the CKP sensor electrical connector.
6. Fill the cooling system and engine block. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
7. Lower the vehicle.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
2. Drain the cooling system and engine block. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. If necessary, disconnect the crankshaft position (CKP) sensor electrical connector.
4. Remove the thermal bypass hose bolt.
5. Reposition the thermal bypass hose clamp.
6. Remove the thermal bypass hose from the fitting.

1. Install the thermal bypass hose to the fitting.
2. Position the thermal bypass hose clamp. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Install the thermal bypass hose bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
4. If necessary, connect the CKP sensor electrical connector.
5. Fill the cooling system and engine block. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
6. Lower the vehicle.

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. Remove the radiator inlet hose from the water outlet tube.
4. Open the clip and remove the wiring harness branch from the bracket.
5. Remove the bolt and wiring harness bracket at the thermostat housing.
6. Remove the main engine electrical harness connector bolts.
7. Disconnect the turbocharger vane position sensor electrical connector.
8. Remove the main electrical harness bracket bolts.
9. Remove the main electrical harness bracket.
10. Disconnect the turbocharger coolant inlet hose from the turbocharger bypass valve.
11. Remove the water outlet bolts.
12. Remove the water outlet.
13. Remove and discard the O-ring seal.

1. Install a NEW O-ring seal to the water outlet.
2. Lubricate the O-ring seal with clean engine coolant.
3. Install the water outlet.
4. Install the water outlet bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
5. Connect the turbocharger coolant inlet hose to the turbocharger bypass valve.
6. Install the main electrical harness bracket.
7. Install the main electrical harness bracket bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
8. Connect the turbocharger vane position sensor electrical connector.
9. Install the main engine electrical harness connector bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
10. Install the wiring harness bracket and bolt to the thermostat housing. Tighten: Tighten the bolt to 10 N.m (89 lb in).
11. Install the wiring harness branch to the bracket and close the clip.
12. Install the radiator inlet hose to the water outlet tube.
13. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
14. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Remove the radiator outlet hose. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the water pump inlet bolts.
3. Remove the water pump inlet and thermostat from the water pump.

1. Install the thermostat and thermostat housing to the water pump.
2. Install the thermostat housing bolts. Tighten: Tighten the bolts to 15 N.m (11 lb ft).
3. Install the radiator outlet hose. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Loosen the air cleaner outlet duct clamp at the mass airflow/intake air temperature (MAF/IAT) sensor.
3. Remove the positive crankcase ventilation (PCV) hose.
4. Remove the air cleaner adapter nut.
5. In order to remove the air cleaner outlet duct, pivot the duct upward until the hinge clip releases from the lip on the throttle body.
6. Reposition the inlet hose clamp at the water outlet.
7. Remove the inlet hose from the water outlet.
8. Remove the water outlet studs.
9. Remove the water outlet.
10. Remove the thermostat.
11. Clean the sealing surface of the water outlet.
12. Clean the sealing surface of the intake manifold.
13. Remove and discard the O-ring seal.

1. Install a NEW O-ring seal to the thermostat.
2. Install the thermostat.
3. Install the water outlet.
4. Install the water outlet studs. Tighten: Tighten the studs to 25 N.m (18 lb ft).
5. Install the inlet hose to the water outlet.
6. Position the inlet hose clamp at the water outlet.
7. Align the hinge clip with the lip on the throttle body. In order to install the air cleaner outlet duct, pivot the air cleaner outlet duct downward until the mounting stud is through the hole.
8. Install the air cleaner adapter nut.
9. Install the PCV hose.
10. Tighten the air cleaner outlet duct clamp at the MAF/IAT sensor. Tighten: Tighten the clamps to 4 N.m (35 lb in).
11. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
12. Inspect the cooling system for leaks.

1. Remove the water outlet. Refer to «Water Outlet Tube Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the bolt for the fuel line bracket.
3. Remove the fuel line bracket.
4. Remove the thermostat housing cover bolts.
5. Remove the thermostat housing cover.
6. Remove the thermostats and seals.

Inspection Procedure

1. Inspect the thermostats for sticking, cracks, and/or leakage of wax.
2. Replace the thermostats if damage is found.
3. Clean the thermostat housing and thermostat housing cover sealing surfaces.

1. Install the thermostats and seals to the thermostat housing. The rear thermostat (4) has 2 vent valves. Install with the vent valves towards the rear of engine.
2. Install the thermostat housing cover.
3. Install the thermostat housing cover bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
4. Install the fuel line bracket.
5. Install the fuel line bracket bolt. Tighten: Tighten the bolt to 21 N.m (15 lb ft).
6. Install the water outlet tube. Refer to «Water Outlet Tube Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Reposition the inlet hose clamp at the water outlet.
3. Remove the inlet hose from the water outlet.
4. Remove the water outlet bolts (2).
5. Remove the water outlet (1).
6. Remove the thermostat (3).

1. Install the thermostat (3).
2. Install the water outlet (1). NOTE: Refer to «FASTENER NOTICE»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Install the water outlet bolts (2). Tighten: Tighten the bolts to 30 N.m (22 lb ft).
4. Install the inlet hose to the water outlet.
5. Position the inlet hose clamp at the water outlet.
6. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
3. Disconnect the negative battery cables. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
6. Disconnect the air conditioning (A/C) compressor clutch electrical connector (5).
7. Disconnect the A/C cut out switch electrical connector.
8. Remove the A/C compressor bolts.
9. Reposition the A/C compressor, with the hoses attached, to the right side of the engine compartment.
10. Remove the generator positive cable to generator nut.
11. Remove the positive cable from the generator.
12. Remove the clip holding the positive cable to the engine front cover.
13. Remove the battery positive cable junction block to power steering pump bolt (1).
14. Move the generator positive cable and the junction block bracket aside.
15. Disconnect the generator electrical connector.
16. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
17. Remove the air conditioning (A/C) compressor/power steering pump bracket bolts.
18. Reposition the A/C compressor/power steering pump bracket and secure to the side. Do not remove the power steering pump from the bracket. The hoses and battery cables can remain on the power steering pump.
19. Remove the heater outlet hose bracket bolt from the generator bracket.
20. Remove the idler pulley.
21. Remove the generator bracket bolts.
22. Remove the generator bracket and position to the side. The generator does not require removal. The drive belt tensioner does not require removal.
23. Remove the oil fill tube. Refer to «Oil Fill Tube Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
24. Remove the water outlet. Refer to «Water Outlet Tube Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
25. Reposition the exhaust gas recirculation (EGR) hose clamp at the EGR coolant pipe.
26. Remove the EGR coolant pipe bolt.
27. Remove the EGR coolant pipe with O-ring seal from the crossover.
28. Reposition the turbocharger coolant return pipe hose clamp.
29. Remove the turbocharger coolant return pipe hose.
30. Remove the fuel line bracket bolt at the thermostat housing crossover.
31. Remove the cooling fan pulley. Refer to «Cooling Fan Pulley Replacement (6.6L (LLY) Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
32. Remove the water pump inlet pipe bolts.
33. Remove the thermostat housing bolts and nuts.
34. Remove the thermostat housing, with the bypass pipe.
35. Remove and discard the thermostat bypass pipe to water pump O-ring seal.
36. Remove and discard the thermostat housing gaskets.
37. If necessary, perform the following steps: Remove the thermostat bypass pipe from the thermostat housing. Remove and discard the thermostat bypass pipe O-ring seal. Remove the thermostat cover bolts and cover. Remove the thermostats. Remove and discard the thermostat seals.
38. If required, clean and inspect the thermostat housing. Refer to «Engine Coolant Thermostat Housing Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-4-of-5__engine-coolant-thermostat-housing-cleaning-and) .

1. If necessary, perform the following steps: Install NEW seals to the thermostats. Install the thermostats. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) . Install the thermostat cover and bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft). Install a NEW O-ring seal to the thermostat bypass pipe. Install the thermostat bypass pipe to the thermostat housing.
2. Install a NEW thermostat bypass pipe to water pump O-ring seal.
3. Install the thermostat housing using NEW gaskets.
4. Install the thermostat housing bolts and nuts Tighten: Tighten the bolts/nuts to 21 N.m (15 lb ft).
5. Install the water pump inlet pipe bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
6. Install the cooling fan pulley. Refer to «Cooling Fan Pulley Replacement (6.6L (LLY) Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Install the fuel line bracket bolt at the thermostat housing crossover. Tighten: Tighten the bolt to 21 N.m (15 lb ft).
8. Install the turbocharger coolant return pipe hose.
9. Position the turbocharger coolant return pipe hose clamp.
10. Install the EGR coolant pipe with O-ring seal to the crossover.
11. Install the EGR coolant pipe bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
12. Position the EGR hose clamp at the EGR coolant pipe.
13. Install the water outlet. Refer to «Water Outlet Tube Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
14. Install the oil fill tube. Refer to «Oil Fill Tube Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
15. Position the generator bracket.
16. Install the generator bracket bolts. Tighten: Tighten the bolt to 50 N.m (37 lb ft).
17. Install the idler pulley. Tighten: Tighten the bolt to 43 N.m (32 lb ft).
18. Install the heater outlet hose bracket bolt to the generator bracket. Tighten: Tighten the bolt to 21 N.m (15 lb ft).
19. Position the A/C compressor/power steering pump bracket.
20. Install the A/C compressor/power steering pump bracket bolts. Tighten: Tighten the bolt to 46 N.m (34 lb ft).
21. Position the generator positive cable and the junction block bracket.
22. Install the battery positive cable junction block to power steering pump bolt (1). Tighten: Tighten the bolt to 9 N.m (80 lb in).
23. Install the clip holding the positive cable to the engine front cover.
24. Install the positive cable to the generator.
25. Install the generator positive cable to generator nut. Tighten: Tighten the nut to 9 N.m (80 lb in).
26. Connect the ECT sensor electrical connector.
27. Connect the generator electrical connector.
28. Position the A/C compressor, with the hoses attached.
29. Install the A/C compressor bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
30. Connect the A/C cut out switch electrical connector.
31. Connect the A/C compressor clutch electrical connector (5).
32. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
33. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (Manual Transmission - Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
34. Connect the negative battery cables. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
35. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
36. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
3. Reposition the inlet hose clamp at the water crossover.
4. Remove the inlet hose from the water crossover.
5. Reposition the heater inlet hose clamp at the water crossover.
6. Remove the heater inlet hose from the water crossover.
7. Reposition the bypass hose clamps at the water crossover and water pump.
8. Remove the bypass hose.
9. Remove the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L Engines)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
10. Remove the power steering pump. Refer to «Power Steering Pump Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (6.6L Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) .
11. Remove the generator bracket bolts and nut.
12. Remove the generator bracket stud.
13. Remove the generator bracket.
14. Remove the water crossover bolts.
15. Remove the water crossover.
16. Remove and discard the water crossover gaskets.
17. If replacing the water crossover remove the following: Water outlet bolts (2) Water outlet (1) Thermostat (3)

1. If replacing the water crossover install the following: Thermostat (3) Water outlet (1) Water outlet bolts (2) Tighten: Tighten the bolts to 30 N.m (22 lb ft).
2. Install NEW water crossover gaskets.
3. Install the water crossover.
4. Install the water crossover bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
5. Install the generator bracket.
6. Install the generator bracket stud. Tighten: Tighten the stud to 20 N.m (15 lb ft).
7. Install the generator bracket bolts and nut. Tighten: Tighten the bolts and nut to 50 N.m (37 lb ft).
8. Install the power steering pump. Refer to «Power Steering Pump Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (6.6L Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Pump Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) .
9. Install the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L Engines)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
10. Install the bypass hose.
11. Position the bypass hose clamps at the water crossover and water pump.
12. Install the heater inlet hose to the water crossover.
13. Position the heater inlet hose clamp at the water crossover.
14. Install the inlet hose to the water crossover.
15. Position the inlet hose clamp at the water crossover.
16. Install the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
17. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the coolant air bleed pipe bolts/studs (1).
3. Remove the coolant air bleed pipe (2) with gaskets (3).
4. Remove the coolant air bleed pipe cover bolts (1) and covers (2).
5. Remove the gaskets from the coolant air bleed pipe and covers.
6. Discard the gaskets.
7. Remove the coolant air bleed hose (1) from the pipe (2).

1. Install the coolant air bleed hose (1) onto the pipe (2).
2. Install the gaskets onto the coolant air bleed pipe and covers.
3. Install the coolant air bleed pipe (2) and gaskets (3) onto the cylinder heads.
4. Install the coolant air bleed pipe bolts/studs (1). Tighten: Tighten the bolts/studs to 12 N.m (106 lb in).
5. Install the coolant air bleed pipe covers (2) and bolts (1). Tighten: Tighten the bolts to 12 N.m (106 lb in).
6. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Reposition the coolant air bleed hose clamp at the throttle body.
2. Remove the coolant air bleed hose from the throttle body.
3. Reposition the coolant air bleed hose clamp at the pipe.
4. Remove the coolant air bleed hose (1) from the pipe (2).

1. Install the coolant air bleed hose (1) to the pipe (2).
2. Position the coolant air bleed hose clamp at the pipe.
3. Install the coolant air bleed hose to the throttle body.
4. Position the coolant air bleed hose clamp at the throttle body.
5. Add engine coolant, if necessary.

1. Remove the thermostat housing. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the bypass pipe from the thermostat housing.
3. Remove and discard the O-ring seals from the bypass pipe and the water pump.
4. Clean the sealing surfaces of the bypass pipe.
5. If required, clean and inspect the bypass pipe and thermostat housing. Refer to «Engine Coolant Thermostat Housing Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-4-of-5__engine-coolant-thermostat-housing-cleaning-and) .

1. Install a NEW O-ring seal onto the bypass pipe.
2. Install a NEW O-ring seal to the water pump.
3. Lubricate the O-ring seals with clean engine coolant.
4. Install the bypass pipe into the thermostat housing.
5. Install the thermostat housing. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

J 41240 Fan Clutch Remover and Installer. See Special Tools .

1. Loosen the air cleaner outlet duct clamp at the mass air flow (MAF)/intake air temperature (IAT) sensor.
2. Remove the positive crankcase ventilation (PCV) hose.
3. Remove the air cleaner adapter nut.
4. In order to remove the air cleaner outlet duct, pivot the duct upward until the hinge clip release from the lip on the throttle body.
5. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
6. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
7. Reposition the radiator outlet hose clamps at the surge tank and water pump.
8. Remove the radiator outlet hose from the surge tank.
9. Remove the radiator outlet hose from the water pump.
10. Reposition the water pump inlet hose clamps.
11. Remove the water pump inlet hose.
12. Using J 41240 , hold the water pump pulley, remove the water pump pulley bolts. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) .
13. Remove the water pump bolts.
14. Remove the water pump.
15. Remove and discard the water pump gaskets.
16. Clean and inspect the water pump, if necessary. Refer to «Water Pump Cleaning and Inspection»(ref-277938-S11131167422008012100000) .

1. If reusing the old fasteners, apply sealant GM P/N 12346004, (Canadian P/N 10953480), or equivalent to the threads of the water pump bolts.
2. Install NEW water pump gaskets and the water pump. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Install the water pump bolts. Tighten: Tighten the bolts to 45 N.m (33 lb ft).
4. Using J 41240 , hold the water pump pulley, install the water pump pulley bolts. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__special-tools) . Tighten: Tighten the bolts to 25 N.m (18 lb ft).
5. Install the water pump inlet hose.
6. Position the water pump inlet hose clamps.
7. Install the radiator outlet hose to the water pump.
8. Install the radiator outlet hose to the surge tank.
9. Position the radiator outlet hose clamps at the surge tank and water pump.
10. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
11. Align the hinge clip with the lip on the throttle body. In order to install the air cleaner outlet duct, pivot the air cleaner outlet duct downward until the mounting stud is through the hole.
12. Install the air cleaner adapter nut.
13. Install the PCV hose.
14. Tighten the air cleaner outlet duct clamp at the MAF/IAT sensor. Tighten: Tighten the clamps to 4 N.m (35 lb in).
15. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
16. Inspect the cooling system for leaks.

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet duct.
4. Remove the air cleaner outlet duct.
5. If necessary, remove the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Upper Intake Manifold Sight Shield Replacement (6.0L (RPO LQ9))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
6. Remove the radiator vent inlet hose from the radiator hose clips.
7. Reposition the inlet hose clamp at the water pump.
8. Remove the inlet hose from the water pump.
9. If necessary, remove the fan blade. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
10. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory (4.8L, 5.3L, and 6.0L Engines)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Drive Belt Replacement - Accessory (5.3L Engine w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
11. Reposition the outlet hose clamp at the water pump.
12. Remove the outlet hose from the water pump.
13. Reposition the surge tank outlet hose clamp at the water pump.
14. Remove the surge tank outlet hose from the water pump.
15. Reposition the heater inlet hose clamp at the water pump.
16. Remove the heater inlet hose from the water pump.
17. Remove the water pump bolts.
18. Remove the water pump and gaskets.
19. Discard the water pump gaskets.

1. Install the water pump and NEW gaskets.
2. Install the water pump bolts. Tighten: Tighten the bolts a first pass to 15 N.m (11 lb ft). Tighten the bolts a final pass to 30 N.m (22 lb ft).
3. Install the heater inlet hose to the water pump.
4. Position the heater inlet hose clamp at the water pump.
5. Install the surge tank outlet hose to the water pump.
6. Position the surge tank outlet hose clamp at the water pump.
7. Install the outlet hose to the water pump.
8. Position the outlet hose clamp at the water pump.
9. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory (4.8L, 5.3L, and 6.0L Engines)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Drive Belt Replacement - Accessory (5.3L Engine w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
10. If necessary, install the fan blade. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Install the inlet hose to the water pump.
12. Position the inlet hose clamp at the water pump.
13. Install the engine vent inlet hose to the radiator hose clips.
14. If necessary, install the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement (4.8L, 5.3L, and 6.0L (RPO LQ4))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) or «Upper Intake Manifold Sight Shield Replacement (6.0L (RPO LQ9))»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
15. Install the air cleaner outlet duct.
16. Install the radiator inlet hose clip to the outlet duct.
17. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten: Tighten the clamps to 4 N.m (35 lb in).
18. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
3. Remove the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Clutch Replacement (Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Reposition the outlet hose clamp at the water pump.
5. Remove the outlet hose from the water pump.
6. Reposition the bypass hose clamps at the water pump and water crossover.
7. Remove the bypass hose.
8. Remove the water pump bolts.
9. Remove the water pump.
10. Remove and discard the water pump gaskets.

1. Place NEW water pump gaskets into place.
2. Install the water pump. NOTE: Refer to «FASTENER NOTICE»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Install the water pump bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
4. Install the bypass hose.
5. Position the bypass hose clamps at the water pump and water crossover.
6. Install the outlet hose to the water pump.
7. Position the outlet hose clamp at the water pump.
8. Install the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Clutch Replacement (Gasoline)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
9. Install the drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
10. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Remove the left wheelhouse inner panel. Refer to «Wheelhouse Panel Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
2. Remove the thermostat housing crossover. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
4. Remove the water pump to engine coolant pipe nuts.
5. Remove the engine wiring harness retainer from the inner stud.
6. Remove the water pump bolts. Note the location of the bolts. The bolts are three different lengths.
7. Remove the water pump.
8. Remove and discard the water pump O-ring and coolant pipe gasket.
9. If required, clean and inspect the water pump. Refer to «Water Pump Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-4-of-5__water-pump-cleaning-and-inspection) .

1. Lubricate the water pump O-ring with engine oil.
2. Install the engine coolant pipe gasket and water pump O-ring.
3. Install the water pump. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
4. Install the water pump bolts. Ensure the correct length bolt is used in the proper location. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
5. Install the engine wiring harness retainer on the water pump outlet pipe inner stud.
6. Install the water pump to engine coolant pipe nuts. Tighten: Tighten the nuts to 21 N.m (15 lb ft).
7. Install the thermostat housing crossover. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
9. Install the left wheelhouse inner panel. Refer to «Wheelhouse Panel Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .

1. Remove the water pump. Refer to «Water Pump Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Water Pump Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Water Pump Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Water Pump Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the engine coolant pipe.
3. Remove and discard the coolant pipe O-ring seal.

1. Install a NEW O-ring seal onto the coolant pipe.
2. Lubricate the O-ring seal with engine coolant.
3. Install the engine coolant pipe.
4. Install the water pump. Refer to «Water Pump Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Water Pump Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Water Pump Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Water Pump Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Reposition the front heater inlet hose clamp (4) from the auxiliary water pump (1).
3. Remove the front heater inlet hose (6) from the auxiliary water pump (1).
4. Reposition the rear heater inlet hose clamp (2) from the auxiliary water pump (1).
5. Remove the rear heater inlet hose (3) from the auxiliary water pump (1).
6. Remove the heater outlet hose from the clip.
7. Disconnect the electrical connector (1) from the auxiliary water pump (2).
8. Remove the nuts (4) from the auxiliary water pump bracket (1).
9. Remove the auxiliary water pump (1) from the vehicle.
10. Remove the clips (2) from the auxiliary water pump bracket (1).
11. Remove the auxiliary water pump (3) from the auxiliary water pump bracket (1).

1. Install the auxiliary water pump (3) to the auxiliary water pump bracket (1).
2. Install the clips (2) to the auxiliary water pump bracket (1).
3. Install the auxiliary water pump (1) to the vehicle.
4. Install the nuts (4) to the auxiliary water pump bracket (1). Tighten: Tighten the nuts to 9 N.m (80 lb in).
5. Connect the electrical connector (1) to the auxiliary water pump (2).
6. Install the heater outlet hose to the clip.
7. Install the rear heater inlet hose (3) to the auxiliary water pump (1).
8. Position the rear heater inlet hose clamp (2) to the auxiliary water pump (1).
9. Install the front heater inlet hose (6) to the auxiliary water pump (1).
10. Position the front heater inlet hose clamp (4) to the auxiliary water pump (1).
11. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Loosen the air cleaner outlet duct clamps from the throttle body.
2. Loosen the air cleaner outlet duct clamps from the mass airflow sensor.
3. Remove the air cleaner outlet duct.
4. Remove the A/C line retainer from the fan shroud.
5. Remove the engine harness clip from the powertrain control module (PCM) cover.
6. Remove the transmission control module (TCM) cover bolts.
7. Remove TCM cover from the fan shroud.
8. Loosen the TCM electrical connector bolts.
9. Disconnect the TCM electrical connectors (1).
10. Remove the TCM and cover.
11. Remove the fan shroud retainers (1).
12. Remove the fan shroud bolts (2).
13. Remove the upper fan shroud.

1. Install the upper fan shroud.
2. Install the fan shroud retainers (1).
3. Install the fan shroud bolts (2). Tighten: Tighten the bolts to 9 N.m (80 lb in).
4. Connect the TCM electrical connectors (1).
5. Install the TCM and cover.
6. Tighten the TCM electrical connector bolts. Tighten: Tighten the bolts to 8 N.m (71 lb in).
7. Install the TCM cover to the fan shroud.
8. Install the TCM cover bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
9. Install the engine harness clip to the PCM cover.
10. Install the A/C line retainer to the fan shroud.
11. Install the air cleaner outlet duct.
12. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten: Tighten the clamp to 4 N.m (35 lb in).
13. Tighten the air cleaner outlet duct clamp at the mass airflow sensor. Tighten: Tighten the clamp to 4 N.m (35 lb in).

1. Loosen the air cleaner outlet duct clamps from the throttle body.
2. Loosen the air cleaner outlet duct clamps from the mass airflow sensor.
3. Remove the air cleaner outlet duct.
4. Remove the A/C line retainer from the fan shroud.
5. Remove the engine harness clip from the powertrain control module (PCM) cover.
6. Remove the transmission control module (TCM) cover bolts.
7. Remove TCM cover from the fan shroud.
8. Loosen the TCM electrical connector bolts.
9. Disconnect the TCM electrical connectors (1).
10. Remove the TCM and cover.
11. Remove the fan shroud retainers.
12. Remove the fan shroud bolts
13. Remove the upper fan shroud.

1. Install the upper fan shroud.
2. Install the fan shroud bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
3. Install the fan shroud retainers.
4. Connect the TCM electrical connectors (1).
5. Install the TCM and cover.
6. Tighten the TCM electrical connector bolts. Tighten: Tighten the bolts to 8 N.m (71 lb in).
7. Install the TCM cover to the fan shroud.
8. Install the TCM cover bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
9. Install the engine harness clip to the PCM cover.
10. Install the A/C line retainer to the fan shroud.
11. Install the air cleaner outlet duct.
12. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten: Tighten the clamp to 4 N.m (35 lb in).
13. Tighten the air cleaner outlet duct clamp at the mass airflow sensor. Tighten: Tighten the clamp to 4 N.m (35 lb in).

1. Loosen the air cleaner outlet duct clamps from the throttle body.
2. Loosen the air cleaner outlet duct clamps from the mass airflow sensor.
3. Remove the air cleaner outlet duct.
4. If equipped remove the throttle body heater hose retainer from the fan shroud.
5. If equipped remove the inlet radiator hose retainer from the fan shroud.
6. Remove the fan shroud retainers.
7. Remove the fan shroud bolts (2).
8. Remove the upper fan shroud.

1. Install the upper fan shroud. NOTE: Refer to «FASTENER NOTICE»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
2. Install the fan shroud retainers (1)
3. Install the fan shroud bolts (2). Tighten: Tighten the bolts to 9 N.m (80 lb in).
4. If equipped install the inlet radiator hose retainer to the fan shroud.
5. If equipped install the throttle body heater hose retainer to the fan shroud.
6. Install the air cleaner outlet duct.
7. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten: Tighten the clamp to 4 N.m (35 lb in).
8. Tighten the air cleaner outlet duct clamp at the mass airflow sensor. Tighten: Tighten the clamp to 4 N.m (35 lb in).

1. Loosen the air cleaner outlet duct clamps from the throttle body.
2. Loosen the air cleaner outlet duct clamps from the mass airflow sensor.
3. Remove the air cleaner outlet duct.
4. If equipped remove the throttle body heater hose retainer from the fan shroud.
5. If equipped remove the inlet radiator hose retainer from the fan shroud.
6. Remove the fan shroud retainers.
7. Remove the fan shroud bolts
8. Remove the upper fan shroud.

1. Install the upper fan shroud.
2. Install the fan shroud bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
3. Install the fan shroud retainers.
4. If equipped install the inlet radiator hose retainer to the fan shroud.
5. If equipped install the throttle body heater hose retainer to the fan shroud.
6. Install the air cleaner outlet duct.
7. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten: Tighten the clamp to 4 N.m (35 lb in).
8. Tighten the air cleaner outlet duct clamp at the mass airflow sensor. Tighten: Tighten the clamp to 4 N.m (35 lb in).

1. Loosen the air cleaner outlet duct clamps from the throttle body.
2. Loosen the air cleaner outlet duct clamps from the mass air flow (MAF) sensor.
3. Remove the air cleaner outlet duct.
4. Remove the hybrid control module (HCM). Refer to «Powertrain Control Interface Module Replacement (5.3L Engine w/RPO HP2)»(ref-277905-S13537703952008012100000) .
5. Remove the throttle body heater hose retainer from the fan shroud.
6. Remove the inlet radiator hose retainer from the fan shroud.
7. Remove the fan shroud retainers.
8. Remove the fan shroud bolts.
9. Remove the upper fan shroud (1).

1. Install the upper fan shroud (1).
2. Install the fan shroud bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
3. Install the fan shroud retainers.
4. Install the inlet radiator hose retainer to the fan shroud.
5. Install the throttle body heater hose retainer to the fan shroud.
6. Install the HCM. Refer to «Powertrain Control Interface Module Replacement (5.3L Engine w/RPO HP2)»(ref-277905-S13537703952008012100000) .
7. Install the air cleaner outlet duct.
8. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten: Tighten the clamp to 4 N.m (35 lb in).
9. Tighten the air cleaner outlet duct clamp at the MAF sensor. Tighten: Tighten the clamp to 4 N.m (35 lb in).

1. Remove the cooling fan. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. If equipped with engine oil cooler, remove the oil cooler hose clip from the lower fan shroud.
3. Lift the lower fan shroud up in order to disengage the fan shroud from the retaining clips on the radiator.

1. Install the lower fan shroud to the retaining clips on the radiator and firmly push down.
2. If equipped with the engine oil cooler, Install the oil cooler hose clip to the lower fan shroud.
3. Install the cooling fan. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the radiator outlet hose for the 4.3L engine, or the 4.8L, 5.3L and 6.0L engines. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Disconnect the engine oil cooler lines from the radiator, if necessary. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Disconnect the transmission oil cooler lines from the radiator, if necessary. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(ref-277952-S11288139652008012100000) .
5. Remove the radiator bolts.
6. Remove the radiator.

1. Install the radiator.
2. Install the radiator bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
3. Connect the transmission oil cooler lines to the radiator, if necessary. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(ref-277952-S11288139652008012100000) .
4. Connect the engine oil cooler lines to the radiator, if necessary. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Install the radiator outlet hose for the 4.3L engine, or the 4.8L, 5.3L and 6.0L engines. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Install the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the radiator inlet hose for the 8.1L engine. Refer to «Radiator Inlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the radiator outlet hose for the 8.1L engine. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the lower fan shroud. Refer to «Engine Coolant Fan Lower Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
5. Remove the push pin from the air cleaner adapter (2).
6. Remove the bolts from the air cleaner adapter (2).
7. Remove the air cleaner adapter (2) from the vehicle.
8. Reposition the surge tank inlet hose clamp at the radiator.
9. Remove the surge tank inlet hose from the radiator.
10. Disconnect the engine oil cooler lines from the radiator, if necessary. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Disconnect the transmission oil cooler lines from the radiator, if necessary. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(ref-277952-S11288139652008012100000) for the 4L80-E/4L65-E transmission, or «Transmission Fluid Cooler Hose/Pipe Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2) for the Allison transmission.
12. Remove the radiator bolts.
13. Remove the radiator.

1. Install the radiator.
2. Install the radiator bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
3. Connect the transmission oil cooler lines to the radiator, if necessary. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(ref-277952-S11288139652008012100000) for the 4L80-E/4L85-E transmission, or «Transmission Fluid Cooler Hose/Pipe Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2) for the Allison transmission.
4. Connect the engine oil cooler lines to the radiator, if necessary. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Install the surge tank inlet hose to the radiator.
6. Reposition the surge tank inlet hose clamp at the radiator.
7. Install the air cleaner adapter (2) to the vehicle.
8. Install the bolts to the air cleaner adapter (2). Tighten: Tighten the bolts to 9 N.m (80 lb in).
9. Install the push pin to the air cleaner adapter (2).
10. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
11. Install the lower fan shroud. Refer to «Engine Coolant Fan Lower Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
12. Install the radiator outlet hose for the 8.1L engine. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
13. Install the radiator inlet hose for the 8.1L engine. Refer to «Radiator Inlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the radiator inlet hose for the 6.6L engine. Refer to «Radiator Inlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the radiator outlet hose for the 6.6L engine. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the engine fan. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Remove the lower fan shroud. Refer to «Engine Coolant Fan Lower Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. If necessary, disconnect the automatic transmission oil cooler lines from the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2) .
6. Remove the radiator bolts.
7. Remove the radiator.

1. Install the radiator.
2. Install the radiator bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
3. If necessary, connect the automatic transmission oil cooler lines to the radiator. Refer to «Transmission Fluid Cooler Hose/Pipe Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2) .
4. Install the lower fan shroud. Refer to «Engine Coolant Fan Lower Shroud Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Install the engine fan. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Install the radiator outlet hose for the 6.6L engine. Refer to «Radiator Outlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Outlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
7. Install the radiator inlet hose for the 6.6L engine. Refer to «Radiator Inlet Hose Replacement (4.3L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (5.3L w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (6.6L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Inlet Hose Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the radiator. Refer to «Radiator Replacement (4.3, 4.8, 5.3, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the radiator air baffle retainers.
3. Remove the radiator air baffles.

1. Install the radiator air baffles.
2. Install the radiator air baffle retainers.
3. Install the radiator. Refer to «Radiator Replacement (4.3, 4.8, 5.3, and 6.0L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Radiator Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the radiator air upper baffle retainers.
2. Remove the radiator air upper baffle.

1. Install the radiator air upper baffle.
2. Install the radiator air upper baffle retainers.

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
3. Disconnect the coolant heater electrical connector (2).
4. Remove the coolant heater from the engine block.
5. Remove any burrs, sealer, paint or other rough spots.

1. If re-using the old coolant heater, apply thread sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent to the threads.
2. Install the coolant heater to the engine block. Tighten: Tighten the coolant heater to 50 N.m (37 lb ft).
3. Connect the coolant heater electrical connector (2).
4. Lower the vehicle.
5. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Remove the engine protection shield. Refer to «Engine Protection Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
2. Remove the front drive axle shield. Refer to «Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/differentials-drive-axles/#front-drive-axle) .
3. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
5. Disconnect the coolant heater electrical connector.
6. Remove the coolant heater from the engine block.
7. Remove any burrs, sealer, paint or other rough spots.

1. If reusing the old coolant heater, apply thread sealant to the to the threads. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-1-of-4__sealers-adhesives-and-lubricants) for the correct part number.
2. Install the coolant heater to the engine block. Tighten: Tighten the coolant heater to 50 N.m (37 lb ft).
3. Connect the coolant heater electrical connector.
4. Lower the vehicle.
5. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
6. Install the front drive axle shield. Refer to «Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/differentials-drive-axles/#front-drive-axle) .
7. Install the engine protection shield. Refer to «Engine Protection Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the right front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
3. Remove the right engine mount. Refer to «Engine Mount Replacement - Right Side»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
4. Disconnect the engine coolant heater cord.
5. Loosen the coolant heater bolt.
6. Remove the engine coolant heater from the engine block.
7. Do not score the machined surface of the hole.
8. Grasp the plug with pliers.
9. Pull the plug from the engine block.
10. Clean the core plug hole in order to remove the following substances: Burrs Compound Paint Rough spots

1. Coat the O-ring seal and the cleaned surface of the plug opening with water resistant high-temperature grease lubricant GM P/N 1052196 (Canadian P/N 5264008), or the equivalent.
2. Align the coolant heater element to point towards the top of the engine.
3. Tightly push the coolant heater into the engine block.
4. Tighten the bolt on the engine coolant heater until both of the locking wings draw tightly against the inner wall of the engine block. Tighten: Tighten the bolt to 2 N.m (18 lb in).
5. Connect the heater cord to the coolant heater.
6. Remove the right engine mount. Refer to «Engine Mount Replacement - Right Side»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
7. Install the right front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
8. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
9. Inspect for coolant leaks.

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Disconnect the block heater cord from the block heater.
3. Remove the engine block heater.

1. Apply sealant GM P/N 12346004, (Canadian P/N 10953480), or equivalent to the threads of the engine block heater.
2. Install the engine block heater into the block. Tighten: Tighten the coolant heater to 60 N.m (40 lb ft).
3. Connect the block heater cord to the block heater.
4. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Disconnect the heater cord from the coolant heater (4).
3. Loosen the coolant heater bolt.
4. Remove the coolant heater from the engine block.
5. Do not score the machined surface of the hole.
6. Grasp the plug with pliers.
7. Pull the plug from the engine block.
8. Clean the core plug hole in order to remove the following substances: Burrs Compound Paint Rough spots

1. Coat the O-ring seal and the cleaned surface of the plug opening with water resistant high-temperature grease lubricant GM P/N 9985164 (Canadian P/N 10953480), or the equivalent.
2. Tightly push the coolant heater (1) into the engine block.
3. Tighten the coolant heater bolt until both of the locking wings draw tightly against the inner wall of the engine block. Tighten: Tighten the bolt to 2 N.m (18 lb in).
4. Connect the heater cord to the coolant heater (4).
5. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
6. Inspect the cooling system for leaks.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the coolant heater electrical connector (2).
3. Remove the coolant heater cord retainer and bolts.
4. Remove the coolant heater cord.

Note. The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.

1. Install the coolant heater cord.
2. Install the coolant heater cord bolts and retainer. Tighten: Tighten the bolts to 8 N.m (71 lb in).
3. Connect the coolant heater electrical connector (2).
4. Lower the vehicle.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the coolant heater cord from the coolant heater.
3. Remove the coolant heater cord clip (2) from the front brake pipe front pipe.
4. Remove the coolant heater cord retainer (1) and bolt (4). Ensure that the washer (3) is also removed.
5. Remove the coolant heater cord.

Note. The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.

1. Install the coolant heater cord.
2. Install the coolant heater cord retainer (1) and bolt (4). Ensure that the washer (3) is installed under the cord clip and on the bolt (4). Tighten: Tighten the bolt to 8 N.m (71 lb in).
3. Install the coolant heater cord clip (2) to the front brake pipe front pipe.
4. Connect the coolant heater cord to the coolant heater.
5. Lower the vehicle.

Cooling Fan Control - Two Fan System

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the engine control module (ECM) to operate both fans together at low or high speeds. The cooling fans receive positive voltage from the cooling fan relays which receive battery positive voltage from the underhood fuse block. The fan relay coils receive ignition 1 voltage from the powertrain relay.

During low speed operation, the ECM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the low speed fan relay coil, closes the relay contacts, and supplies battery positive voltage from the low fan fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan series/parallel relay and the right cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the ECM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. The ECM grounds the high speed fan relay and the cooling fan series/parallel relay through the high speed cooling fan relay control circuit. This energizes the cooling fan control relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the high speed fan relay coil is energized closing the relay contacts and provides battery positive voltage from the high fan fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have their own ground path. The result is a parallel circuit with both fans running at high speed.

Schematic Reference

Engine Cooling Schematics

Engine Coolant Indicators

ENGINE COOLANT HOT

The instrument panel cluster (IPC) displays ENGINE COOLANT HOT message when the IPC receives a class 2 message from the powertrain control module (PCM) requesting illumination of this driver warning.

ENGINE OVERHEATED

The IPC displays ENGINE OVERHEATED message when the IPC receives a class 2 message from the PCM requesting illumination of this driver warning.

LOW COOLANT LEVEL B

The IPC displays LOW COOLANT LEVEL message when the IPC receives a class 2 message from the PCM requesting illumination of this driver warning.

REDUCED ENGINE POWER

The IPC displays REDUCED ENGINE POWER message when the IPC detects a reduced engine power condition from the PCM. The IPC receives a class 2 message from the PCM requesting illumination when the engine temperature reaches 132°C (270°F).

The engine cooling fan system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the powertrain control module (PCM) to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood fuse block.

During low speed operation, the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the low speed fan relay coil, closes the relay contacts, and supplies battery positive voltage from the low fan fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan s/p relay and the right cooling fan. The result is a series circuit with both fans running at low speed.

During high speed operation the PCM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. After a 3 second delay, the PCM supplies a ground path for the high speed fan relay and the cooling fan s/p relay through the high speed cooling fan relay control circuit. This energizes the cooling fan s/p relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the high speed fan relay coil is energized closing the relay contacts and provides battery positive voltage from the high fan fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.

The PCM commands the low speed cooling fans ON under the following conditions

1. Engine coolant temperature exceeds approximately 104.25°C (220°F).
2. A/C refrigerant pressure exceeds 1447 kPa (210 psi).
3. After the vehicle is shut OFF if the engine coolant temperature at key-off is greater than 101°C (214°F) the low speed fans will run for a minimum of 60 seconds After 60 seconds, if the coolant temperature drops below 101°C (214°F) the fans will shut OFF. The fans will automatically shut OFF after 3 min. regardless of coolant temperature.

The PCM commands the high speed fans ON under the following conditions

1. Engine coolant temperature exceeds approximately 107.2°C (220°F).
2. A/C refrigerant pressure exceeds approximately 1824 kPa (265 psi).
3. When certain DTCs set.

At idle and very low vehicle speeds the cooling fans are only allowed to increase in speed if required. This insures idle stability by preventing the fans from cycling between high and low speed.

Coolant Level Control (If Equipped)

The engine cooling system contains an engine coolant level switch to alert the driver in the event of a coolant loss. The powertrain control module (PCM) sends out a coolant loss signal over the coolant level switch signal circuit. When the engine coolant level switch reads a low coolant level in the fill tank, the switch opens. The message center receives its power from engine wiring harness junction block on the battery positive voltage circuit. Ground is provided by the ground circuits via the body wiring harness junction block and the engine wiring harness junction block. The cluster receives the class 2 message from the PCM indicating Low Coolant and displays the LOW COOLANT LEVEL message on the driver information center (DIC).

Coolant Heater

The optional engine coolant heater (RPO K05) operates using 110-volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather -18°C (0°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.

Auxiliary Coolant Pump (w/HP2)

The auxiliary coolant pump circulates coolant through the engine and heater core when HVAC requires heating and the engine is HOT and OFF. The HCM will turn on the auxiliary coolant pump when the HVAC control module commands it to do so by sending a class 2 signal to the HCM.

The cooling system's function is to maintain an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system is designed to remove approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the coolant does not flow to the radiator until the thermostat opens. This allows the engine to warm quickly.

Cooling Cycle

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. Coolant will then be pumped through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders, where it absorbs heat.

Some coolant is also pumped from the water pump to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost.

The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.

Coolant is also directed to the throttle body. There it circulates through passages in the casting. During initial start up, the coolant assists in warming the throttle body. During normal operating temperatures, the coolant assists in regulating the throttle body temperature.

Cooling Cycle (6.6L Diesel Engine)

Coolant is drawn from the radiator outlet and into the water pump inlet by the water pump. The coolant flows to the heater core while the engine is running. This provides the passenger compartment with heat and defrost.

Coolant is then pumped through the water pump outlet and through the coolant pipe to the engine oil cooler. The coolant flows around the oil cooler element and to the rear engine cover. The rear engine cover distributes the coolant flow to both banks of the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.

The coolant is then forced through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.

Coolant is also directed to the turbocharger. There it circulates through passages in the center housing. During engine warm-up cycle the bypass valve located in the turbocharger inlet hose at the outlet pipe prevents coolant flow. During normal operating temperatures, the coolant assists in keeping the turbocharger cool.

From the cylinder heads, the coolant flows to the thermostats. The coolant flows from the thermostat housing to the water pump through the bypass pipe until the enginereaches 85°C (185°F).

Operation of the cooling system requires proper functioning of all cooling system components. The cooling system consists of the following components

Coolant

The engine coolant is a solution made up of a 50-50 mixture of DEX-COOL and suitable drinking water. The coolant solution carries excess heat away from the engine to the radiator, where the heat is dissipated to the atmosphere.

Radiator

The radiator is a heat exchanger. It consists of a core and two tanks. The aluminum core is a tube and fin crossflow design that extends from the inlet tank to the outlet tank. Fins are placed around the outside of the tubes to improve heat transfer to the atmosphere.

The inlet and outlet tanks are a molded, high temperature, nylon reinforced plastic material. A high temperature rubber gasket seals the tank flange edge to the aluminum core. The tanks are clamped to the core with clinch tabs. The tabs are part of the aluminum header at each end of the core.

The radiator also has a drain cock located in the bottom of the left hand tank. The drain cock unit includes the drain cock and drain cock seal.

The radiator removes heat from the coolant passing through it. The fins on the core transfer heat from the coolant passing through the tubes. As air passes between the fins, it absorbs heat and cools the coolant.

Surge Tank

The surge tank is a plastic tank with a threaded pressure cap. The tank is mounted at a point higher than all other coolant passages. The surge tank provides an air space in the cooling system that allows the coolant to expand and contract. The surge tank provides a coolant fill point and a central air bleed location.

During vehicle use, the coolant heats and expands. The increased coolant volume flows into the surge tank. As the coolant circulates, any air is allowed to bubble out. Coolant without air bubbles absorbs heat much better than coolant with bubbles.

Pressure Cap

The pressure cap seals the cooling system. It contains a blow off or pressure relief valve and a vacuum or atmospheric valve. The pressure valve is held against its seat by a spring, which protects the radiator from excessive cooling system pressure. The vacuum valve is held against its seat by a spring, which permits opening of the valve to relieve vacuum created in the cooling system as it cools off. The vacuum, if not relieved, might cause the radiator and/or coolant hoses to collapse.

The pressure cap allows cooling system pressure to build up as the temperature increases. As the pressure builds, the boiling point of the coolant increases. Engine coolant can be safely run at a temperature much higher than the boiling point of the coolant at atmospheric pressure. The hotter the coolant is, the faster the heat transfers from the radiator to the cooler, passing air.

The pressure in the cooling system can get too high. When the cooling system pressure exceeds the rating of the pressure cap, it raises the pressure valve, venting the excess pressure.

As the engine cools down, the temperature of the coolant drops and a vacuum is created in the cooling system. This vacuum causes the vacuum valve to open, allowing outside air into the surge tank. This equalizes the pressure in the cooling system with atmospheric pressure, preventing the radiator and coolant hoses from collapsing.

Cooling Fan and Clutch

The engine cooling fan and clutch are driven by the crankshaft via the drive belt. The cooling fan draws air through the radiator to improve the transfer of heat from the coolant to the atmosphere. As the fan blades spin, they pull cool, outside air past the radiator core. The fan clutch drives the cooling fan. The fan clutch controls the amount of torque that is transmitted from the crankshaft to the fan blades. The clutch allows more torque to engage on the fan when the engine operating temperature increases and/or the vehicle speed is low. As the torque increases, the fan turns more quickly. The fan clutch decreases the torque applied to the cooling fan when the engine temperature decreases and/or the vehicle speed is high. As the torque decreases, the fan speed decreases.

Air Baffles and Seals

The cooling system uses deflectors, air baffles and air seals to increase cooling system capability. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle and through the radiator to increase engine cooling. Air baffles are also used to direct airflow through the radiator and increase cooling capability. Air seals prevent air from bypassing the radiator and A/C condenser, and prevent recirculation of hot air for better hot weather cooling and A/C condenser performance.

Water Pump

The water pump is a centrifugal vane impeller type pump. The pump consists of a housing with coolant inlet and outlet passages and an impeller. The impeller is mounted on the pump shaft and consists of a series of flat or curved blades or vanes on a flat plate. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force.

The impeller shaft is supported by one or more sealed bearings. The sealed bearings never need to be lubricated. Grease cannot leak out, dirt and water cannot get in as long as the seal is not damaged or worn.

The purpose of the water pump is to circulate coolant throughout the cooling system. The water pump is driven by the crankshaft via the drive belt.

Water Pump (6.6L Diesel Engine)

The water pump is a centrifugal vane impeller type pump. The water pump is gear driven by the crankshaft gear. The pump consists of a housing with coolant inlet and outlet passages and an impeller. The impeller is a flat plate mounted on the pump shaft with a series of flat or curved blades or vanes. When the impeller rotates, the coolant between the vanes is thrown outward by centrifugal force. The impeller shaft is supported by bearings. Splash of the engine oil lubricates the bearings. The bearings and shaft are sealed to prevent engine oil to mix with the coolant. If the seal fails, coolant will leak out the vent hole in the water pump housing.

The purpose of the water pump is to circulate coolant throughout the cooling system.

Thermostat

The thermostat is a coolant flow control component. It's purpose is to help regulate the operating temperature of the engine. It utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a small piston. When the element is heated, it expands and exerts pressure against the small piston. This pressure forces the valve to open. As the element is cooled, it contracts. This contraction allows a spring to push the valve closed.

When the coolant temperature is below the rated thermostat opening temperature, the thermostat valve remains closed. This prevents circulation of the coolant to the radiator and allows the engine to warm up. After the coolant temperature reaches the rated thermostat opening temperature, the thermostat valve will open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. The thermostat also provides a restriction in the cooling system, after it has opened. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block.

Thermostats (6.6L Diesel Engine)

The thermostats are coolant flow control components. The purpose of the thermostats are to regulate the correct operating temperature of the engine. The thermostats utilizes a temperature sensitive wax-pellet element. The element connects to a valve through a piston. When the element is heated, it expands and exerts pressure against a rubber piston. This pressure forces the valve to open. As the element is cooled, it contracts. This contraction allows a spring to push the valve closed.

The 6.6L diesel engine requires two thermostats for correct coolant flow. The front thermostat is a dual purpose thermostat. The front thermostat controls the coolant flow to the bypass port and to the water outlet. The rear thermostat only controls the coolant flow to the water outlet.

When the coolant temperature is below the rated thermostat opening temperature, the front thermostat valve remains closed to the water outlet and is opened to the bypass port. The bottom portion of the thermostat is raised off of the bypass port while at the same time the top portion closes the coolant flow to the water outlet. The rear thermostat also is closed to the water outlet during engine warm-up. This prevents circulation of the coolant to the radiator and allows the engine to warm up quickly. After the coolant temperature reaches 82°C (180°F) the front thermostat primary valve opening temperature, the front thermostat primary valve will start to open. The coolant is then allowed to circulate through the thermostat to the radiator where the engine heat is dissipated to the atmosphere. As the engine coolant reaches 85°C (185°F) and more coolant demand is required the front thermostat secondary valve begins to close the bypass port and the rear thermostat begins to open coolant flow to the water outlet. The thermostats will continue to control the coolant flow by opening and closing. The front thermostat will be fully open when the coolant temperature reaches 95°C (203°F) the rear thermostat will be fully open when the coolant temperature reaches 100°C (212°F). The thermostat also provides a restriction in the cooling system, even after the it has opened. This restriction creates a pressure difference which prevents cavitation at the water pump and forces coolant to circulate through the engine block.

Engine Oil Cooler

The engine oil cooler is a heat exchanger. It is located inside the left side end tank of the radiator. The engine oil temperature is controlled by the temperature of the engine coolant that surrounds the oil cooler in the radiator.

The engine oil pump, pumps the oil through the engine oil cooler line to the oil cooler. The oil then flows through the cooler where the engine coolant absorbs heat from the oil. The oil is then pumped through the oil cooler return line, to the oil filter, to the engine block oil system.

Engine Oil Cooler (6.6L Diesel Engine)

The engine oil cooler is a heat exchanger. The engine oil cooler is mounted to the left lower corner of the engine. The oil filter is attached to the oil cooler housing. The engine coolant flows around the oil cooler element. The oil cooler element is a series of plates. The engine oil temperature is regulated by the temperature of the engine coolant that surrounds the oil cooler as the engine oil passes through the cooler.

The engine oil pump, pumps the oil through the engine oil feed line to the oil cooler. The oil then flows down through the cooler while the engine coolant absorbs heat from the oil. The oil is then pumped through the oil return line, to the oil filter, then to the main engine oil passage.

Transmission Oil Cooler

The transmission oil cooler is a heat exchanger. It is located inside the right side end tank of the radiator. The transmission fluid temperature is regulated by the temperature of the engine coolant in the radiator.

The transmission oil pump, pumps the fluid through the transmission oil cooler line to the transmission oil cooler. The fluid then flows through the cooler where the engine coolant absorbs heat from the fluid. The fluid is then pumped through the transmission oil cooler return line, to the transmission.

Turbocharger Bypass Valve (6.6L Diesel Engine)

The turbocharger bypass valve is a temperature control valve. The valve is located in the turbocharger coolant inlet hose at the water outlet tube.

The purpose of the valve is to close the coolant flow through the turbocharger. Closing off the coolant flow through the turbocharger avoids turbocharger overcooling.

Special Tools

Special Tools Illustration Tool Number/Description J 24460-01 Cooling System Pressure Tester J 24731 Tempil Stick J 26568 Coolant and Battery Fluid Tester J 38185 Hose Clamp Pliers J 41240 Fan Clutch Remover and Installer J 42401 Radiator Cap/Surge Tank Test Adapter J 43181 Heater Line Q.C. Release Tool J 46143 Cooling System Adapter J 46406 Fan Clutch Remover and Installer

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

See also:
• Diagnostic System Check - Vehicle
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Connector Repairs
• Control Module References
• Checking Aftermarket Accessories
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Circuit Testing
• Diagnostic Repair Verification
• Instrument Cluster Replacement
• Drive Belt Replacement - Accessory (4.8L, 5.3L, and 6.0L Engines)
• Drive Belt Replacement
• Drive Belt Replacement - Accessory
• Cylinder Head Replacement - Left Side
• Cylinder Head Replacement - Right Side
• Engine Coolant/Water in Transmission
• Coolant in Engine Oil
• Coolant in Combustion Chamber
• Coolant in Combustion Chamber
• Coolant in Engine Oil
• Coolant in Combustion Chamber
• Coolant in Engine Oil
• Lifting and Jacking the Vehicle
• Fastener Notice
• Approximate Fluid Capacities
• Air Cleaner Assembly Replacement
• Air Cleaner Assembly Replacement
• Engine Protection Shield Replacement
• Shield Replacement
• Battery Negative Cable Disconnection and Connection (Auxiliary Battery)
• Engine Coolant Thermostat Housing Cleaning and Inspection
• Power Steering Pump Replacement (4.3L)
• Water Pump Cleaning and Inspection
• Transmission Fluid Cooler Hose/Pipe Replacement
• Sealers, Adhesives, and Lubricants
• Tire and Wheel Removal and Installation
• DTC P0480 or P0481
• Engine Overheating
• Symptoms - Engine Cooling
• Engine Overheated Indicator Always On
• Engine Coolant Temperature Indicator Always On
• Loss of Coolant
• Engine Fails To Reach Normal Operating Temperature
• Fan Clutch Diagnosis
• Scan Tool Output Controls
• Radiator Cleaning
• Flushing
• Draining and Filling Cooling System (Static Fill)
• Draining and Filling Cooling System (w/RPO HP2)
• Draining and Filling Cooling System (Vac-N-Fill)
• Cooling System Leak Testing
• Pressure Cap Testing
• Special Tools
• Fastener Tightening Specifications