Heating, Ventilation and Air Conditioning Chevrolet Cab & Chassis Silverado 3500 HD

Fastener Tightening Specifications

Refrigerant System Capacities (Non-HP2)

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

1. The identification of the control modules which are not communicating.
2. The identification of any stored diagnostic trouble codes (DTCs) and their status.

The use of the Diagnostic System Check - Vehicle will identify the correct procedures to begin vehicle diagnosis. These must be performed before system DTC or symptom diagnosis.

Special Tools

1. J-39400-A: Halogen Leak Detector
2. J-41447: R-134A A/C Tracer Dye-Box of 24
3. J-42220: Universal 12V Leak Detection Lamp
4. J-43872: Fluorescent Dye Cleaner
5. J-46297: A/C Dye Injector Kit
6. J-46297-12: Replacement Dye Cartridges

Refrigerant Leak Testing

Note. General Motors vehicles are now manufactured with fluorescent dye installed directly into the air conditioning (A/C) system.

The fluorescent dye mixes and flows with the polyalkylene glycol (PAG) oil throughout the refrigerant system.

Verifying some passive leaks may require using the J-39400-A: detector, even though the A/C system contains fluorescent dye.

The only time that adding additional fluorescent dye is required is after flushing the A/C system.

Fluorescent Leak Detector

Fluorescent dye will assist in locating any leaks in the A/C system.

1. Condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye away from the actual leak. Condensation may also carry dye through the HVAC module drain.
2. Leaks in the A/C system will be indicated in a light green or yellow color when using the leak detection lamp. Use the leak detection lamp in the following areas: All fittings or connections that use seal washers or O-rings All of the A/C components The A/C compressor shaft seal The A/C hoses and pressure switches The HVAC module drain tube, if the evaporator core is suspected of leaking The service port sealing caps The sealing cap is the primary seal for the service ports.
3. Follow the instructions supplied with the J-42220: lamp.
4. To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a rag and the approved J-43872: cleaner.

Fluorescent Dye Injection

1. Not all of the fluorescent dyes are compatible with PAG oil. Some types of dye decrease the oil viscosity or may chemically react with the oil.
2. R-134A leak detection dye requires time to work. Depending upon the leak rate, a leak may not become visible for between 15 minutes and 7 days.
3. To prevent false diagnosis, thoroughly clean any residual dye from the service port with a rag and the approved fluorescent dye cleaner J-43872: dye cleaner.

Halogen Leak Detector

Ensure that the vehicle has at least 0.45 kg (1 lb) of refrigerant in the A/C refrigeration system in order to perform a leak test. Refer to Refrigerant Recovery and Recharging (Non-HP2) or Refrigerant Recovery and Recharging (HP2) for recharging the A/C system.

Note. Halogen leak detectors are sensitive to the following items: Windshield washing solutions Many solvents and cleaners Some adhesives used in the vehicle

Clean and dry all surfaces in order to prevent a false warning. Liquids will damage the detector.

Note. Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

Follow the instructions supplied with the J-39400-A: detector.

Air Conditioning (A/C) System Performance Test (Diesel Engine)

This test measures the operating efficiency of the A/C system under the following conditions

1. The current ambient air temperature
2. The current relative humidity
3. The high side pressure of the A/C system
4. The low side pressure of the A/C system
5. The temperature of the air being discharged into the passenger compartment

Test Description

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

1. 1: This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
2. 2: This step measures the performance of the A/C system.
3. 3: This step is to allow for vehicle variations as well as high ambient air temperatures.

Scheme 1

A/C Performance Table - Diesel Engine

Air Conditioning (A/C) System Performance Test (Gas Engine w/Electric Cooling Fan)

This test measures the operating efficiency of the A/C system under the following conditions

1. The current ambient air temperature
2. The current relative humidity
3. The high side pressure of the A/C system
4. The low side pressure of the A/C system
5. The temperature of the air being discharged into the passenger compartment

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

1. 1: This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
2. 2: This step measures the performance of the A/C system.
3. 3: This step is to allow for vehicle variations as well as high ambient air temperatures.

Scheme 2

A/C Performance Table - Gas Engine With Electric Cooling Fan or RPO HP2

Air Conditioning (A/C) System Performance Test (Gas Engine w/Engine Driven Fan)

This test measures the operating efficiency of the A/C system under the following conditions

1. The current ambient air temperature
2. The current relative humidity
3. The high side pressure of the A/C system
4. The low side pressure of the A/C system
5. The temperature of the air being discharged into the passenger compartment

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

1. 1: This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
2. 2: This step measures the performance of the A/C system.
3. 3: This step is to allow for vehicle variations as well as high ambient air temperatures.

A/C System Pressure Zone Classification - Gas Engine With Engine Driven Cooling Fan

A/C Performance Table - Gas Engine With Engine Driven Cooling Fan

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

1. 1: This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
2. 2: This step measures the performance of the A/C system.
3. 3: This step is to allow for vehicle variations as well as high ambient air temperatures.

Scheme 3

A/C Performance Table with Aux A/C

Air Conditioning (A/C) Diagnostics - Pressure Zone A

Air Conditioning (A/C) Diagnostics - Pressure Zone B

Air Conditioning (A/C) Diagnostics - Pressure Zone C

Air Conditioning (A/C) Diagnostics - Pressure Zone D

Heating Performance Diagnostic

Defrosting Insufficient

Noise Diagnosis - Blower Motor

Air Conditioning Compressor Oil Diagnosis

Note. To avoid repeat compressor failure, always inspect the condition of the refrigerant oil and take the appropriate corrective action before installing the replacement compressor.

Noise Diagnosis - Air Conditioning (A/C) System

Noise Diagnosis - HVAC Module

Odor Diagnosis

Eliminating Air Conditioning Odor

Odors may be emitted from the air conditioning system primarily at start up in hot, humid climates. The following conditions may cause the odor

1. Debris is present in the HVAC module.
2. Microbial growth on the evaporator core

When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. To remove odors of this type, the microbial growth must be eliminated. Perform the following procedure

Deodorize the evaporator core using Deodorizing Aerosol Kit.

Perform the following steps in order to deodorize the A/C system

1. Ensure that the plenum which draws outside air into the HVAC module is clear of debris.
2. Disable the A/C compressor clutch operation by disconnecting the clutch coil electrical connector.
3. Dry the evaporator core by performing the following steps: Start the engine. Select the warmest temperature setting. Select the recirculation mode. Run the blower motor on high for 10 minutes.
4. Locate an area in the air conditioning duct between the blower motor and the evaporator core downstream of the blower motor.
5. Drill a 3.175 mm (0.125 in) hole where the hole will not interfere with or damage the following components: The blower motor The evaporator core Any other operating part the of system
6. Wear safety goggles and latex gloves in order to perform the following actions: Select the maximum blower speed. Insert the deodorizer extension tube into the hole to the mark on the extension tube. Use short spray bursts and vary the direction of spray for a 2-3 minute period of time.
7. Shut the engine OFF. Allow the vehicle to sit for 3-5 minutes.
8. Seal the 3.175 mm (0.125 in) hole with body sealer or RTV gasket compound.
9. Start the engine.
10. Operate the blower motor on high for 15-20 minutes to dry.
11. Reconnect the A/C compressor clutch coil electrical connector.
12. Verify proper clutch operation.

1. J 43600: ACR 2000 Air Conditioning Service Center
2. J 45037: A/C Oil Injector

For equivalent regional tools, refer to Special Tools .

The J 43600: service center is a complete air conditioning service center for R-134a. The ACR 2000 recovers, recycles, evacuates and recharges A/C refrigerant quickly, accurately and automatically. The unit has a display screen that contains the function controls and displays prompts that will lead the technician through the recover, recycle, evacuate and recharge operations. R-134a is recovered into and charged out of an internal storage vessel. The ACR 2000 automatically replenishes this vessel from an external source tank in order to maintain a constant 5.45-6.82 kg (12-15 lbs) of A/C refrigerant.

The ACR 2000 has a built in A/C refrigerant identifier that will test for contamination, prior to recovery and will notify the technician if there are foreign gases present in the A/C system. If foreign gases are present, the ACR 2000 will not recover the refrigerant from the A/C system.

The ACR 2000 also features automatic air purge, single pass recycling and an automatic oil drain.

Refer to the J 43600: service center ACR 2000 manual for operation and setup instruction. Always recharge the A/C System with the proper amount of R-134a. Refer to Refrigerant System Capacities (Non-HP2) for the correct amount.

A/C Refrigerant System Oil Charge Replenishing

If oil was removed from the A/C system during the recovery process or due to component replacement, the oil must be replenished. Oil can be injected into a charged system using J 45037: injector. For the proper quantities of oil to add to the A/C refrigerant system, refer to Refrigerant System Capacities (Non-HP2) .

1. J 43600: ACR 2000 Air Conditioning Service Center
2. J 45037: A/C Oil Injector
3. GE 48997: Hybrid A/C Oil Injector Adapter Hose

For equivalent regional tools, refer to Special Tools .

The J 43600: service center is a complete air conditioning service center for R-134a. The ACR 2000 recovers, recycles, evacuates and recharges A/C refrigerant quickly, accurately and automatically. The unit has a display screen that contains the function controls and displays prompts that will lead the technician through the recover, recycle, evacuate and recharge operations. R-134a is recovered into and charged out of an internal storage vessel. The ACR 2000 automatically replenishes this vessel from an external source tank in order to maintain a constant 5.45-6.82 kg (12-15 lbs) of A/C refrigerant.

The ACR 2000 has a built in A/C refrigerant identifier that will test for contamination, prior to recovery and will notify the technician if there are foreign gases present in the A/C system. If foreign gases are present, the ACR 2000 will not recover the refrigerant from the A/C system.

The ACR 2000 also features automatic air purge, single pass recycling and an automatic oil drain.

Refer to the J 43600: service center manual for operation and setup instruction. Always recharge the A/C System with the proper amount of R-134a. Refer to Refrigerant System Capacities (Non-HP2) for the correct amount.

If POE oil was removed from the A/C system during the recovery process or due to component replacement, the oil must be replenished. POE Oil can be injected into a charged system using J 45037: injector along with GE 48997: adapter hose. For the proper quantities of oil to add to the A/C refrigerant system, refer to Refrigerant System Capacities (Non-HP2) .

1. J 41447 Leak Detection Dye. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. J 42220 Universal 12V Leak Detection Lamp. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. J 43600 ACR 2000 Refrigerant Station. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
4. J 45268 Flush Adapter Kit. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Flushing is intended to remove the following

1. Contaminated PAG oil
2. Desiccant, following a desiccant bag failure
3. Overcharge of PAG oil
4. Refrigerant contamination

Flushing Procedure

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the orifice tube. Refer to «Expansion (Orifice) Tube Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Connect the A/C lines with the orifice tube removed.
4. Remove the A/C compressor. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
5. Install J 45268 -3 to the A/C compressor hose assembly. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
6. Forward flow refrigerant flushing is recommended for contaminated refrigerant or PAG oil. Perform the following procedure: IMPORTANT: The filter inside J 45268 -1 is serviceable. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Remove and discard the check valve from the filter. Service the filter with ACDelco P/N GF 470, before each flush. Connect J 45268 -1 flush filter to the suction port of the J 45268 flush adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Connect the blue hose from the J 43600 to J 45268 flush filter adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Connect the red hose from the J 43600 to J 45268 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
7. Reverse flow refrigerant flushing is recommended for desiccant bag failure only. Perform the following procedure and replace the accumulator when the flush is complete: IMPORTANT: The filter inside the J 45268-1 is serviceable. Remove and discard the check valve from the filter. Service the filter with ACDelco P/N GF 470, before each flush. Connect the J 45268-1 flush filter to the discharge port of J 45268 flush adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Connect the blue hose from J 43600 to J 45268 flush filter adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Connect the red hose from J 43600 to the suction port of J 45268 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
8. Flush the A/C system. Follow the instructions supplied with the J 43600 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
9. Remove the J 45268 from the A/C compressor hose assembly. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
10. Drain the PAG oil from the A/C compressor. Rotate the compressor input shaft to assist in draining the PAG oil from the compressor.
11. Add back the total system capacity of PAG oil to the A/C compressor. Refer to «Refrigerant System Capacities (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities-non-hp2) .
12. Add one bottle of J 41447 directly to the A/C Compressor. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
13. Install the A/C compressor. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
14. Inspect the orifice tube for debris. Clean or replace as needed.
15. Install the orifice tube. Refer to «Expansion (Orifice) Tube Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
16. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
17. Leak test the fittings using the J 42220 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. J 41447 Leak Detection Dye. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. J 42220 Universal 12V Leak Detection Lamp. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. J 43600 ACR 2000 Air Conditioning Service Center. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
4. J 45268 Flush Adapter Kit. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Flushing is intended to remove the following contaminants

1. Contaminated polyalkylene glycol (PAG) oil
2. Desiccant, following a desiccant bag failure
3. Overcharge of PAG oil
4. Refrigerant contamination

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the orifice tube. Refer to «Expansion (Orifice) Tube Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Connect the A/C lines with the orifice tube removed.
4. Remove the A/C compressor. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
5. Inspect the end of the suction hose for a suction screen.
6. Remove the suction screen, if installed.
7. Install J 45268-4 to the A/C compressor suction hose.
8. Install J 45268-5 to the A/C compressor discharge hose.
9. Forward flow refrigerant flushing is recommended for contaminated refrigerant or PAG oil. Perform the following procedure: IMPORTANT: The filter inside the J 45268-1 is serviceable. Remove and discard the check valve from the filter. Service the filter with ACDelco P/N GF 470, before each flush. Connect the J 45268-1 flush filter to the suction port of the J 45268-4 flush adapter. Connect the blue hose from the J 43600 to the J 45268-1 flush filter adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Connect the red hose from the J 43600 to the J 45268-5 flush adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
10. Reverse flow refrigerant flushing is recommended for desiccant bag failure. Perform the following procedure and replace the accumulator when the flush procedure is complete. IMPORTANT: The filter inside the J 45268-1 is serviceable. Remove and discard the check valve from the filter. Service the filter with AC P/N GF 470, before each flush. Connect the J 45268-1 flush filter to the discharge port of the J 45268-5 flush adapter. Connect the blue hose from the J 43600 to the J 45268-1 flush filter adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . Connect the red hose from the J 43600 to the suction port of the J 45268-4 flush adapter. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . IMPORTANT: Close the valve on the external refrigerant tank, before starting the flush process. Flush the front A/C system. Follow the instructions supplied with the J 43600 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
11. Remove the J 45268-4 from the A/C compressor suction hose.
12. Remove the J 45268-5 from the A/C compressor discharge hose.
13. If the removed A/C compressor is being reinstalled, perform the following procedure: Drain the PAG oil from the A/C compressor. Rotate the compressor input shaft to assist in draining the PAG oil from the A/C compressor. Add the total system capacity of PAG oil to the A/C compressor. Refer to «Refrigerant System Capacities (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities-non-hp2) .
14. If you will replace the A/C compressor after flushing the system, perform the following procedure: Determine if the new service compressor is shipped with PAG oil. Refer to the «Refrigerant System Capacities (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities-non-hp2) . If the service compressor is shipped with PAG oil, DO NOT drain the new PAG oil from the compressor. Deduct the amount of PAG oil shipped with the service compressor from the amount of PAG oil listed in the capacities table. Refer to «Refrigerant System Capacities (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities-non-hp2) . Add the calculated amount to the compressor, as needed.
15. Add one bottle of J 41447 directly to the A/C compressor. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
16. Install the A/C compressor. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
17. Install a new orifice tube. Refer to «Expansion (Orifice) Tube Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
18. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
19. Leak test the fittings using J 42220 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Draining Procedure

1. Before draining oil, position the compressor vertically (clutch facing upwards) and let it sit for 1 minute.
2. Position the compressor horizontally, with the ports facing downward, rotate the clutch and shake the compressor in order to remove as much oil from the compressor as possible.
3. Drain the oil from both the suction and discharge ports of the removed compressor into a clean, graduated container. Rotate the compressor shaft to assist in draining the compressor.
4. Measure and record the amount of oil drained from the removed compressor. This measurement will be used during installation of the replacement compressor. Inspect oil drained from removed compressor. Refer to «Air Conditioning Compressor Oil Diagnosis»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__air-conditioning-compressor-oil-diagnosis)
5. Properly discard the used refrigerant oil.

Balancing Procedure

1. Before installing the compressor, the refrigerant oil will have to be fully drained.
2. Add back the same quantity of polyalkylene glycol (PAG) oil as drained from the removed compressor. Refer to the amount of refrigerant oil recorded during the compressor removal.

1. GE-48997 A/C POE Oil Injector (HP2). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. J 39400-A Halogen Leak Detector. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. J 45037 A/C Oil Injector. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Remove the A/C compressor from the vehicle. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Drain the oil from both the suction and discharge ports of the removed compressor into a clean, graduated container.
3. Measure and record the amount of oil drained from the removed compressor. This measurement will be used during installation of the replacement compressor.
4. Inspect oil drained from the removed compressor. Refer to «Air Conditioning Compressor Oil Diagnosis»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__air-conditioning-compressor-oil-diagnosis) .
5. Properly discard the used POE refrigerant oil.

Balancing Procedure with Service Compressor Replacement (Flushing Not Required)

1. Before installing the compressor, calculate the total amount of oil drained from the compressor and collected by the recovery equipment.
2. If the amount drained and recorded is: LESS THAN 74 ml (2.5 ounces), leave 74 ml (2.5 ounces) in the replacement compressor. Do not drain the oil from the replacement compressor. MORE THAN 74 ml (2.5 ounces), calculate the difference between the amount that was drained and recorded. ADD the calculated difference to the A/C system by filling the A/C compressor or using J 45037: injector along with GE 48997: adapter.

Balancing Procedure with Service Compressor Replacement (Flushing Required)

1. Flush the A/C system. Flushing will remove all the oil from the A/C system. Refer to «Flushing (Non HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Flushing (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the A/C compressor from the vehicle. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) . The A/C system must be replenished with 150 ml (5.0 oz.) of POE oil. NOTE: The refrigerant oil in the A/C system must be balanced during compressor replacement. The new service compressor is shipped with 74 ml (2.5 oz.) of refrigerant oil. Do not drain the oil from the compressor.
3. Before installing the compressor, deduct the amount of oil shipped with the compressor 74 ml (2.5 oz.) from the total amount of the system oil 150 ml (5.0 oz.).
4. Add the calculated amount 76 ml (2.5 oz.) of oil to the compressor and install it in the vehicle.

Balancing Procedure (Flushing Required Only)

1. Flush the A/C system. Flushing will remove all the oil from the A/C system. Refer to «Flushing (Non HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Flushing (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the A/C compressor from the vehicle. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Drain the oil from both the suction and discharge ports of the removed compressor into a clean, graduated container.
4. Add the total system capacity of POE oil 150 ml (5.0 oz.) to the A/C system by filling the A/C compressor or using J 45037: injector along with GE 48997: adapter.

J 39400-A Halogen Leak Detector. See Special Tools .

Removal Procedure

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Install a ratchet into the belt tensioner adapter opening.
3. Rotate the belt tensioner counterclockwise in order to relieve the tension on the belt.
4. Remove the belt from the A/C compressor.
5. Slowly release the tension on the belt tensioner.
6. Remove the discharge hose bolt (2) from the A/C compressor (3).
7. Remove the discharge hose (1) from the A/C compressor (3).
8. Remove the suction hose bolt (2) from the A/C compressor (3).
9. Remove the suction hose (1) from the A/C compressor (3).
10. Discard the sealing washers. Cap all of the openings.
11. Disconnect the electrical connections.
12. Remove the A/C compressor mounting bolts.
13. If replacing the A/C compressor. Refer to «Air Conditioning Compressor Oil Balancing (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Oil Balancing (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Installation Procedure

1. Remove the caps or tape from the hose and line ends.
2. Install the A/C compressor.
3. Install the A/C compressor mounting bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
4. Connect the electrical connection.
5. Install the A/C discharge hose (1) to the compressor (3) using new sealing washers.
6. Install the A/C discharge hose bolt (2) to the A/C compressor (3). Tighten: Tighten the bolt to 16 N.m (12 lb ft).
7. Install the A/C suction hose (1) to the compressor (3) using new sealing washers.
8. Install the A/C suction hose bolt (2) to the A/C compressor (3). Tighten: Tighten the bolt to 16 N.m (12 lb ft).
9. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/mechanical/#engine-mechanical-66l-2-of-5) .
10. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
11. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Install a ratchet into the belt tensioner adapter opening.
3. Rotate the belt tensioner counterclockwise in order to relieve the tension on the belt.
4. Remove the belt from the A/C compressor.
5. Slowly release the tension on the belt tensioner.
6. Remove the discharge and suction hose bolt from the A/C compressor.
7. Remove the discharge and suction hose from the A/C compressor.
8. Discard the sealing washers. Cap all of the openings.
9. Disconnect the electrical connections.
10. Remove the A/C compressor mounting bolts.
11. If replacing the A/C compressor. Refer to «Air Conditioning Compressor Oil Balancing (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Oil Balancing (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Remove the caps or tape from the hose and line ends.
2. Install the A/C compressor.
3. Install the A/C compressor mounting bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
4. Connect the electrical connection.
5. Install the A/C discharge and suction hose to the compressor using new sealing washers.
6. Install the A/C discharge and suction hose bolt to the A/C compressor. Tighten: Tighten the bolt to 16 N.m (12 lb ft).
7. Install the drive belt. Refer to «Drive Belt Replacement»(ref-317247-S12080742082009060900000) .
8. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
9. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Install a ratchet into the air conditioning (A/C) belt tensioner adapter opening.
3. Remove the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/testing-diagnostics/#engine-controls-and-fuel-48l-53l-60l-62l-introduction-1-of-2) .
4. Rotate the A/C belt tensioner clockwise in order to relieve the tension on the belt.
5. Remove the A/C belt from the A/C compressor.
6. Slowly release the tension on the A/C belt tensioner.
7. Remove the discharge hose bolt from the A/C compressor.
8. Remove the discharge hose from the A/C compressor.
9. Remove the suction hose bolt from the A/C compressor.
10. Remove the suction hose from the A/C compressor.
11. Discard the sealing washers. Cap all of the openings.
12. Disconnect the electrical connections.
13. Remove the A/C compressor mounting bolts. The lower right bolt (3) will stay with the compressor due to a lack of clearance.
14. Remove the A/C compressor (2) from the bracket (1).
15. If replacing the A/C compressor. Refer to «Air Conditioning Compressor Oil Balancing (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Oil Balancing (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Install the A/C compressor (2) to the bracket (1) through the fender well. Insert the mounting bolt (3) into the lower right mounting boss before installing the A/C compressor.
2. Install the A/C compressor to the bracket. Insert the mounting bolt into the lower right mount before installing the A/C compressor.
3. Install the A/C compressor mounting bolts and tighten to 50 N.m (37 lb ft).
4. Connect the electrical connector to the A/C compressor.
5. Install the A/C discharge hose to the compressor using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
6. Install the A/C discharge hose bolt to the A/C compressor and tighten to 16 N.m (12 lb ft).
7. Install the A/C suction hose to the compressor using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
8. Install the A/C suction hose bolt to the A/C compressor and tighten to 16 N.m (12 lb ft).
9. Install the A/C drive belt. Refer to «Air Conditioning Compressor Belt Replacement (V8)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/mechanical/#engine-mechanical-48l-53l-60l-62l-2-of-5) .
10. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
11. Install the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/testing-diagnostics/#engine-controls-and-fuel-48l-53l-60l-62l-introduction-1-of-2) .
12. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 4

Scheme 5

Air Conditioning Clutch Drive Plate Adjustment

1. Install the clutch plate assembly.
2. Measure the air gap between the pulley and the drive plate. Adjust the shims to achieve a 0.35-0.65 mm (0.014-0.026 in) air gap.
3. Install the clutch plate retaining bolt and tighten to 18 N.m (13 lb ft).

1. Remove the A/C compressor. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the A/C belt tensioner bolts.
3. Remove the A/C belt tensioner.
4. Remove the A/C compressor bracket mounting bolts.
5. Remove the A/C compressor bracket.

1. Install the A/C compressor bracket.
2. Install the A/C compressor bracket mounting bolts and tighten to 50 N.m (37 lb ft).
3. Install the A/C belt tensioner.
4. Install the A/C belt tensioner bolts and tighten to 50 N.m (37 lb ft).
5. Install the A/C compressor. Refer to «Air Conditioning Compressor Replacement (LLY/LMM)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LU3)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (LY2, LY5, LH6, L76, L92 and LMG)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Air Conditioning Compressor Replacement (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 6

1. Remove the seal washer from the A/C refrigerant component.
2. Inspect the seal washer for signs of damage to help determine the root cause of the failure.
3. Inspect the A/C refrigerant components for damage or burrs. Repair if necessary.
4. Discard the sealing washer.

1. Inspect the new seal washer for any signs of cracks, cuts, or damage. Do not use a damaged seal washer.
2. Remove the cap or tape from the A/C refrigerant components.
3. Using a lint-free clean, dry cloth, clean the sealing surfaces of the A/C refrigerant components.
4. Carefully install the new seal washer onto the A/C refrigerant component. The washer must completely bottom against the surface of the fitting.
5. Assemble the remaining A/C refrigerant components. Refer to the appropriate repair procedure.

1. Disassemble the A/C refrigerant components. Refer to the appropriate repair procedure For compression style fittings use a back up wrench on the fitting (2) and loosen the fitting nut (1). For banjo style fittings remove the bolt retaining the banjo type fitting.
2. Remove the O-ring seal from the A/C refrigerant component.
3. Inspect the O-ring seal for signs of damage to help determine the root cause of the failure.
4. Inspect the A/C refrigerant components for damage or burrs. Repair if necessary.
5. Cap or tape the A/C refrigerant components.
6. Discard the O-ring seal.

1. Inspect the new O-ring seal for any sign or cracks, cuts, or damage. Replace if necessary.
2. Remove the cap or tape from the A/C refrigerant components.
3. Using a lint-free clean, dry cloth, carefully clean the sealing surfaces of the A/C refrigerant components.
4. Lightly coat the new O-ring seal with mineral base 525 viscosity refrigerant oil.
5. Carefully slide the new O-ring seal onto the A/C refrigerant component.
6. The O-ring seal must be fully seated.
7. Assemble the A/C components. Refer to the appropriate repair procedure. For compression style fittings use a back up wrench on the fitting (2) and tighten the fitting nut (1) to specification. For banjo style fittings install the bolt retaining the banjo type fitting and tighten to specification.

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the discharge hose mounting bolt (2) from the A/C compressor. Discard the bolt.
3. Remove the discharge hose (5) from the A/C compressor.
4. Remove the upper radiator air baffle. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Remove the discharge hose nut from the condenser. Discard the nut.
6. Remove the discharge hose from the condenser.
7. Disconnect the A/C recirculation switch from the discharge hose.
8. Remove the discharge hose from the vehicle.
9. Discard all of the used sealing washers. Cap the system openings.

1. Install the discharge hose to the vehicle.
2. Connect the A/C recirculation switch to the discharge hose.
3. Install the discharge hose to the condenser using new sealing washers.
4. Install the NEW discharge hose nut to the condenser. Tighten: Tighten the nut to 16 N.m (12 lb ft).
5. Install the upper radiator air baffle. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
6. Install the discharge hose (5) to the compressor using new sealing washers.
7. Install the NEW discharge hose mounting bolt (2) to the A/C compressor. Tighten: Tighten the bolt to 16 N.m (12 lb ft).
8. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
9. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the discharge hose mounting bolt (2) from the A/C compressor.
3. Remove the discharge hose (1) from the A/C compressor.
4. Remove the upper radiator baffle. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Remove the discharge hose nut from the condenser.
6. Remove the discharge hose from the condenser.
7. Disconnect the electrical connector from the A/C recirculation switch.
8. Remove the discharge hose from the vehicle.
9. Discard all of the used sealing washers. Cap the system openings.

1. Install the discharge hose (1) to the vehicle.
2. Install the discharge hose to the condenser using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Install the discharge hose nut to the condenser and tighten to 16 N.m (12 lb ft).
4. Install the upper air baffle. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
5. Connect the electrical connector to the A/C recirculation switch.
6. Install the discharge hose (1) to the A/C compressor using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
7. Install the discharge hose mounting bolt and tighten to 16 N.m (12 lb ft).
8. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
9. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 7

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the suction hose mounting bolt (3) from the A/C compressor. Discard the bolt.
3. Remove the suction hose (1) from the compressor.
4. Remove the suction hose nut from the accumulator. Discard the nut.
5. Remove the suction hose from the accumulator.
6. Remove the suction hose from the vehicle.
7. Discard all of the used sealing washers. Cap the system openings.

1. Install the suction hose to the vehicle using new sealing washers.
2. Install the suction hose to the accumulator.
3. Install the NEW suction hose nut to the accumulator. Tighten: Tighten the nut to 16 N.m (12 lb ft).
4. Install the suction hose to the compressor (1).
5. Install the NEW suction hose mounting bolt (3). Tighten: Tighten the bolt to 16 N.m (12 lb ft).
6. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
7. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the upper radiator air baffle and deflector. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(ref-317159-S05750315452009060900000) .
4. Remove the surge tank hold down nut and bolt and position aside.
5. Remove the evaporator tube nut from the evaporator.
6. Disconnect the evaporator tube from the evaporator.
7. Remove the evaporator tube nut from the auxiliary A/C tube, if equipped.
8. Disconnect the evaporator tube from the auxiliary A/C tube, if equipped.
9. Remove the evaporator tube nut from the condenser.
10. Disconnect the evaporator tube from the condenser.
11. Remove the evaporator tube from the vehicle.
12. Discard all of the used sealing washers. Cap all of the open connections.

1. Connect the evaporator tube to the condenser using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Install the evaporator tube nut to the condenser and tighten to 16 N.m (12 lb ft).
3. Connect the evaporator tube to the auxiliary A/C tube using new sealing washers, if equipped. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
4. Install the evaporator tube nut to the auxiliary A/C tube, if equipped, and tighten to 16 N.m (12 lb ft).
5. Install the evaporator tube to the evaporator.
6. Install the evaporator tube nut to the evaporator and tighten to 16 N.m (12 lb ft).
7. Install the surge tank hold down nut and bolt and position aside.
8. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(ref-317159-S05750315452009060900000) .
9. Install the upper radiator air baffle and deflector. Refer to «Radiator Air Upper Baffle and Deflector Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
10. Evacuate and recharge the system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
11. Leak test the fittings of the components using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 8

1. Disconnect the electrical connector from the A/C low pressure switch.
2. Remove the A/C low pressure switch from the accumulator.
3. Remove the O-ring and discard.

1. Install the new O-ring seal to the switch. Refer to «Air Conditioning O-Ring Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Install the A/C low pressure switch to the accumulator and tighten to 6 N.m (53 lb in).
3. Connect the electrical connector to the A/C low pressure switch.
4. Leak test the fittings of the components using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

J 39400-A Halogen Leak Detector. See Special Tools .

1. Disconnect the electrical connector from the A/C refrigerant pressure sensor.
2. Remove the A/C refrigerant pressure sensor (1) from the condenser tube.

1. Install the A/C refrigerant pressure sensor (1). Tighten: Tighten the switch to 6 N.m (53 lb in).
2. Connect the electrical connector to the A/C refrigerant pressure sensor.
3. Leak test the fittings of the components using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
4. Lower the vehicle.

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove tie bar. Refer to «Front End Upper Tie Bar Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
3. Remove the hood stop bracket. Refer to «Hood Stop Bracket Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
4. Remove radiator support bolts (1). Access the bolts from the rear of the upper radiator support.
5. Remove radiator support.
6. Remove the compressor discharge hose assembly bolt from the condenser.
7. Disconnect the compressor discharge hose assembly from the condenser.
8. Remove the evaporator tube nut from the condenser.
9. Disconnect the evaporator tube from the condenser.
10. Remove the insulator retainer bolts and the upper insulator retainers.
11. Remove the condenser from the vehicle.

1. Install the condenser to the vehicle.
2. Install the upper insulator retainers and the insulator retainer bolts. Tighten: Tighten the bolts to 2.4 N.m (21 lb in).
3. Connect the evaporator tube to the condenser using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
4. Install the evaporator tube nut to the condenser. Tighten: Tighten the nut to 16 N.m (12 lb ft).
5. Connect the compressor discharge hose to the condenser using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
6. Install the compressor discharge hose nut to the condenser. Tighten: Tighten the nut to 16 N.m (12 lb ft).
7. Install tie bar. Refer to «Front End Upper Tie Bar Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
8. Install the hood stop bracket. Refer to «Hood Stop Bracket Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
9. Install the radiator support. Access the bolts (1) from the rear of the upper radiator support. Refer to «Radiator Support Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) . Tighten: Tighten the nut to 16 N.m (12 lb ft).
10. Install radiator support bracket bolts (1).
11. Evacuate and recharge the system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
12. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

J 39400-A Halogen Leak Detector. See Special Tools .

1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the fascia.
3. Remove radiator support bolts (1). Access the bolts from the rear of the upper radiator support. Refer to «Radiator Support Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
4. Remove radiator support bracket bolts (1).
5. Remove the compressor discharge hose assembly bolt from the condenser.
6. Disconnect the compressor discharge hose assembly from the condenser.
7. Remove the evaporator tube nut from the condenser.
8. Disconnect the evaporator tube from the condenser.
9. Remove the insulator retainer bolts and the upper insulator retainers.
10. Remove the condenser from the vehicle.

1. Install the condenser to the vehicle.
2. Install the upper insulator retainers and the insulator retainer bolts and tighten to 2.4 N.m (21 lb in).
3. Connect the evaporator tube to the condenser using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
4. Install the evaporator tube nut to the condenser and tighten to 16 N.m (12 lb ft).
5. Connect the compressor discharge hose to the condenser using new sealing washers. Refer to «Air Conditioning System Seal Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
6. Install the compressor discharge hose nut to the condenser and tighten to 16 N.m (12 lb ft).
7. Install the lower bolts to the hood latch support bracket and tighten to 9 N.m (80 lb in).
8. Install the radiator support. Access the bolts (1) from the rear of the upper radiator support. Refer to «Radiator Support Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) . Tighten: Tighten the nut to 16 N.m (12 lb ft).
9. Install radiator support bracket bolts (1).
10. Install the fascia.
11. Evacuate and recharge the system. Refer to «Refrigerant Recovery and Recharging (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) or «Refrigerant Recovery and Recharging (HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
12. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 9

J 43181 Heater Line QC Release Tool

1. Drain the engine coolant. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Using the J 43181 disconnect the inlet heater hose from the heater core. Install the J 43181 to the heater core pipe. 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 inlet hose from the heater core.
3. Using the J 43181 disconnect the surge tank outlet hose from the heater core. Install the J 43181 to the heater core pipe. 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 surge tank outlet hose from the heater core.
4. Remove the upper intake manifold sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/mechanical/#engine-mechanical-48l-53l-60l-62l-2-of-5) .
5. Remove the battery. Refer to «Battery Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/charging-system/#battery-charging-system-starting-system) .
6. Remove the accumulator. Refer to «Air Conditioning Accumulator Replacement (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
7. Remove the instrument panel to the service position. Refer to «Instrument Panel Service Positioning (without SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) or «Instrument Panel Service Positioning (with SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
8. Remove the nuts (2) from the HVAC module (3).
9. Remove the bolts (1) from the HVAC module (3).
10. Remove the HVAC module (3).

1. If replacing the HVAC module, transfer the components from the old HVAC module as necessary.
2. Install the HVAC module (3).
3. Install the nuts (2) to the HVAC module (3). Tighten: Tighten the nuts to 9 N.m (80 lb in).
4. Install the bolts (1) to the HVAC module (3). Tighten: Tighten the bolts to 4 N.m (35 lb in).
5. Connect the electrical harness and the ground connections.
6. Install the HVAC module drain hose.
7. Install the instrument panel. Refer to «Instrument Panel Service Positioning (without SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) or «Instrument Panel Service Positioning (with SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
8. Install the upper intake manifold sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/mechanical/#engine-mechanical-48l-53l-60l-62l-2-of-5) .
9. Install the battery. Refer to «Battery Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/charging-system/#battery-charging-system-starting-system) .
10. Install the accumulator. Refer to «Air Conditioning Accumulator Replacement (Non-HP2)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
11. Install the surge tank outlet hose to the heater core. Firmly push the quick connect onto the heater core pipe until you hear an audible click.
12. Install the inlet heater hose to the heater core. Firmly push the quick connect onto the heater core pipe until you hear an audible click.
13. Fill the engine coolant. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Remove the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. If equipped remove the heat stakes (1) from the HVAC module (2) with a screw driver and a hammer.
3. Disconnect all wiring connections from blower motor, blower motor control module and sensors. Also, remove all wiring from retainers before removal.
4. If equipped remove the screws from the HVAC module assembly.
5. Remove the evaporator cowl gasket from the evaporator.
6. Separate the upper HVAC module assembly (2) from the lower HVAC module assembly (1)
7. Remove the evaporator core (1) from the upper HVAC module assembly (2).

1. Install the evaporator core (1) to the HVAC module assembly (2).
2. Install the upper HVAC module assembly (2) from the lower HVAC module assembly (1)
3. Install the evaporator cowl gasket to the evaporator.
4. Install the screws to the HVAC module assembly. Tighten: Tighten the screws to 2 N.m (18 lb in).
5. Install the HVAC module assembly. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air intake tube.
3. Remove the heater and surge tank hoses from the mounting clip.
4. Squeeze the plastic retainer release tabs.
5. Pull the connection apart.
6. Remove the inlet heater hose from the water pump.
7. Remove the inlet heater hose.

1. Install the inlet heater hose.
2. Install the inlet heater hose to the water pump.
3. Connect the heater hose to the heater core.
4. Install the heater and surge tank hoses to the mounting clip.
5. Install the air intake tube.
6. Fill the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the air intake tube.
3. Remove the heater and surge tank hoses from the mounting clip.
4. Squeeze the plastic retainer release tabs.
5. Pull the connection apart.
6. Remove the outlet heater hose from the water pump.
7. Reposition the outlet heater hose clamp at the surge tank.
8. Remove the outlet heater hose from the surge tank.
9. Remove the outlet heater hose.

1. Install the outlet heater hose.
2. Install the outlet heater hose to the water pump.
3. Install the outlet heater hose to the surge tank.
4. Install the outlet heater hose clamp to the surge tank.
5. Connect the heater and surge tank hoses to the heater core.
6. Pull the heater outlet hose to ensure the connection.
7. Install the heater and surge tank hoses to the mounting clip.
8. Install the air intake tube.
9. Fill the cooling system. Refer to «Cooling System Draining and Filling (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

Scheme 10

Scheme 11

1. If equipped, remove the sound insulator panel. Refer to «Instrument Panel Insulator Replacement (With RPO SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) or «Instrument Panel Insulator Replacement (Without RPO SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Remove the blower motor insulating cover screws.
3. Disconnect the electrical connector from the blower motor.
4. Remove the blower motor insulating cover.
5. Pull the retaining tab down while turning the blower motor counterclockwise in order to disengage the blower motor from the heater/ventilation module.
6. Remove the blower motor.

1. Install the blower motor.
2. Install the blower motor to the heater/ventilation module. Turn the blower assembly clockwise until the retaining tab locks into place.
3. Install the blower motor insulating cover.
4. Connect the electrical connector to the blower motor.
5. Install the blower motor insulating cover screws and tighten to 1.6 N.m (14 lb in).
6. If equipped, install the sound insulator panel. Refer to «Instrument Panel Insulator Replacement (With RPO SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) or «Instrument Panel Insulator Replacement (Without RPO SLT)»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

1. Remove the push pin from the left floor air outlet duct (3).
2. Remove the left floor duct (3) from the right floor air outlet duct (2).

1. Install the left floor air outlet duct (3) to the right floor air outlet duct (2).
2. Install the push pin to the left floor air outlet duct (3).

Scheme 20

1. Remove the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. If equipped remove the heat stakes (1) from the HVAC module (2) with a screwdriver and a hammer.
3. If equipped remove the HVAC module assembly screws.
4. Remove the upper HVAC module case (1) from the lower HVAC module case (2).
5. Remove the right temperature door (4) from the upper HVAC module case (3).

1. Install the right temperature door (4) to the upper HVAC module case (3).
2. Install the upper HVAC module case (1) to the lower HVAC module case (2).
3. Install the screws to the HVAC module assembly. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
4. Install the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Remove the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. If equipped remove the heat stakes (1) from the HVAC module (2) with a screw driver and a hammer.
3. If equipped remove the HVAC module assembly screws.
4. Remove the upper HVAC module case (3) from the lower HVAC module case (10).
5. Remove the air temperature separator plate (5) from the lower HVAC module case (10).
6. Remove the left temperature door (11) from the lower HVAC module case (10).

1. Install the left temperature door (11) to the lower HVAC module case (10).
2. Install the air temperature separator plate (5) to the lower HVAC module case (10).
3. Install the upper HVAC module case (3) to the lower HVAC module case (10).
4. Install the screws to the HVAC module assembly. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
5. Install the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Remove the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. If equipped remove the heat stakes (1) from the HVAC module (2) with a screwdriver and a hammer.
3. If equipped remove the HVAC module assembly screws.
4. Separate the HVAC module assembly.
5. Remove the mode actuator screws.
6. Remove the mode actuator.
7. Remove the mode actuator cam assembly.
8. Remove the defroster door (8).

1. Install the defroster door (8).
2. Install the mode actuator cam assembly.
3. Install the mode actuator.
4. Install the mode actuator screws and tighten to 1.6 N.m (14 lb in).
5. Install the HVAC module assembly halves.
6. Install the screws to the HVAC module assembly and tighten to 1.6 N.m (14 lb in).
7. Install the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Remove the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. If equipped remove the heat stakes (1) from the HVAC module (2) with a screwdriver and a hammer.
3. If equipped remove the HVAC module assembly screws.
4. Separate the HVAC module assembly.
5. Remove the air temperature separator plate (5) from the HVAC module assembly (10).
6. Remove the lower mode door (9) from the HVAC module assembly (10).

1. Install the lower mode door (9) to the HVAC module assembly (10).
2. Install the air temperature separator plate (5) to the HVAC module assembly (10).
3. Install the HVAC module assembly halves.
4. Install the screws to the HVAC module assembly. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
5. Install the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Note. The upper mode door is serviced with the upper HVAC module case.

1. Remove the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Disconnect the electrical connector from the mode actuator.
3. Remove the screws from the mode actuator.
4. Remove the mode actuator from the HVAC module assembly (1).
5. If equipped remove the heat stakes (1) from the HVAC module (2) with a screwdriver and a hammer.
6. If equipped remove the HVAC module assembly screws.
7. Separate the HVAC module assembly.
8. Remove the lever (7) from the upper mode door/upper HVAC module case (6).

1. Install the lever (7) to the upper mode door/upper HVAC module case (6).
2. Install the HVAC module assembly halves.
3. Install the screws to the HVAC module assembly. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
4. Install the mode actuator to the HVAC module assembly.
5. Install the screws to the mode actuator. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
6. Connect the electrical connector to the mode actuator.
7. Install the HVAC module. Refer to «Air Conditioning and Heater Module Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500-hd/2008-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 21

Scheme 22

Engine Coolant

Engine coolant is the essential element of the heating system. The thermostat controls the normal engine operating coolant temperature. The thermostat also creates a restriction for the cooling system that promotes a positive coolant flow and helps prevent cavitation.

Coolant enters the heater core through the inlet heater hose, in a pressurized state. The heater core is located inside the HVAC module. The ambient air drawn through the HVAC module absorbs the heat of the coolant flowing through the heater core. Heated air is distributed to the passenger compartment, through the HVAC module, for passenger comfort. Opening or closing the air temperature door controls the amount of heat delivered to the passenger compartment. The coolant exits the heater core through the return heater hose and recirculated back through the engine cooling system.

A/C Cycle

Refrigerant is the key element in an air conditioning system. R-134a is presently the only EPA approved refrigerant for automotive use. R-134a is a very low temperature gas that can transfer the undesirable heat and moisture from the passenger compartment to the outside air.

The electric A/C compressor is a self contained high voltage inverter, electric motor, and direct coupled compressor. The electric A/C compressor requires the high voltage system on the vehicle to be engaged and operates on command from the climate control panel. The electric A/C compressor has the ability to run and provide cooling performance while the vehicle engine is not running. This feature enables the electric A/C compressor to run at a speed independent of the engine. The control system will command the electric A/C compressor to a speed necessary to maintain a desired cooling level rather than cycle the electric A/C compressor on and off. Limits of operation for the electric A/C compressor are controlled by software within the climate control panel. The electric A/C compressor builds pressure on the vapor refrigerant. Compressing the refrigerant also adds heat to the refrigerant. The refrigerant is discharged from the compressor, through the discharge hose, and forced to flow to the condenser and then through the balance of the A/C system. The A/C system is mechanically protected with the use of a high pressure relief valve. If the A/C refrigerant pressure sensor were to fail or if the refrigerant system becomes restricted and refrigerant pressure continued to rise, the high pressure relief will pop open and release refrigerant from the system.

Compressed refrigerant enters the condenser in a high temperature, high pressure vapor state. As the refrigerant flows through the condenser, the heat of the refrigerant is transferred to the ambient air passing through the condenser. Cooling the refrigerant causes the refrigerant to condense and change from a vapor to a liquid state.

The condenser is located in front of the radiator for maximum heat transfer. The condenser is made of aluminum tubing and aluminum cooling fins, which allows rapid heat transfer for the refrigerant. The semi-cooled liquid refrigerant exits the condenser and flows through the liquid line, to the orifice tube.

The orifice tube is located in the liquid line between the condenser and the evaporator. The orifice tube is the dividing point for the high and the low pressure sides of the A/C system. As the refrigerant passes through the orifice tube, the pressure on the refrigerant is lowered. Due to the pressure differential on the liquid refrigerant, the refrigerant will begin to vaporize at the orifice tube. The orifice tube also meters the amount of liquid refrigerant that can flow into the evaporator.

Refrigerant exiting the orifice tube flows into the evaporator core in a low pressure, liquid state. Ambient air is drawn through the HVAC module and passes through the evaporator core. Warm and moist air will cause the liquid refrigerant to boil inside the evaporator core. The boiling refrigerant absorbs heat from the ambient air and draws moisture onto the evaporator. The refrigerant exits the evaporator through the suction line and back to the compressor, in a vapor state, and completing the A/C cycle of heat removal. At the compressor, the refrigerant is compressed again and the cycle of heat removal is repeated.

The conditioned air is distributed through the HVAC module for passenger comfort. The heat and moisture removed from the passenger compartment will also change form, or condense, and is discharged from the HVAC module as water.

A/C Cycle with Auxiliary

The auxiliary A/C system operates from the vehicles primary A/C system. The front or primary A/C system must be ON to allow the rear A/C system to function.

Refrigerant is the key element in an air conditioning system. R-134a is presently the only EPA approved refrigerant for automotive use. R-134a is an very low temperature gas that can transfer the undesirable heat and moisture from the passenger compartment to the outside air.

The A/C system used on this vehicle is a non cycling system. Non cycling A/C systems use a high pressure switch to protect the A/C system from excessive pressure. The high pressure switch will OPEN the electrical signal, to the compressor clutch, in the event that the refrigerant pressure becomes excessive. After the high and low side of the A/C system pressure equalize, the high pressure switch will CLOSE. Closing the high pressure switch will complete the electrical circuit to the compressor clutch. The A/C system is also mechanically protected with the use of a high pressure relief valve. If the high pressure switch were to fail or if the refrigerant system becomes restricted and refrigerant pressure continued to rise, the high pressure relief will pop open and release refrigerant from the system.

The electric A/C compressor is a self contained high voltage inverter, electric motor, and direct coupled compressor. The electric A/C compressor requires the high voltage system on the vehicle to be engaged and operates on command from the climate control panel. The electric A/C compressor has the ability to run and provide cooling performance while the vehicle engine is not running. This feature enables the electric A/C compressor to run at a speed independent of the engine. The control system will command the electric A/C compressor to a speed necessary to maintain a desired cooling level rather than cycle the electric A/C compressor on and off. Limits of operation for the electric A/C compressor are controlled by software within the climate control panel. The electric A/C compressor builds pressure on the vapor refrigerant. Compressing the refrigerant also adds heat to the refrigerant. The refrigerant is discharged from the compressor, through the discharge hose, and forced to flow to the condenser and then through the balance of the A/C system.

Compressed refrigerant enters the condenser in a high temperature, high pressure vapor state. As the refrigerant flows through the condenser, the heat of the refrigerant is transferred to the ambient air passing through the condenser. Cooling the refrigerant causes the refrigerant to condense and change from a vapor to a liquid state.

The condenser is located in front of the radiator for maximum heat transfer. The condenser is made of aluminum tubing and aluminum cooling fins, which allows rapid heat transfer for the refrigerant. The semi-cooled liquid refrigerant exits the condenser and flows through the liquid line. The liquid line flow is split and the liquid refrigerant flows to both the front or primary A/C system, and to the liquid line for the rear A/C system.

The liquid refrigerant, flowing to the rear A/C system, flows into the rear thermal expansion valve (TXV). The rear TXV is located at the rear evaporator inlet. The TXV is the dividing point for the high and the low pressure sides of the rear A/C system. As the refrigerant passes through the TXV, the pressure on the refrigerant is lowered. Due to the pressure differential on the liquid refrigerant, the refrigerant will begin to boil at the expansion device. The TXV also meters the amount of liquid refrigerant that can flow into the evaporator.

Refrigerant exiting the TXV flows into the evaporator core in a low pressure, liquid state. Ambient air is drawn through the rear A/C module and passes through the evaporator core. Warm and moist air will cause the liquid refrigerant boil inside of the evaporator core. The boiling refrigerant absorbs heat from the ambient air and draws moisture onto the evaporator. The refrigerant exits the evaporator through the suction line and back to the primary A/C systems suction line. Refrigerant in the primary A/C system suction line flows back to the compressor, in a vapor state, and completes the A/C cycle of heat removal. At the compressor, the refrigerant is compressed again and the cycle of heat removal is repeated.

The conditioned air is distributed through the rear A/C module for passenger comfort. The heat and moisture removed from the rear passenger compartment will also change form, or condense, and is discharged from the rear A/C module as water.

Illustration Tool Number/Description GE 48997 A/C POE Oil Injector (HP2) J 26549-E Orifice Tube Remover J 39400-A Halogen Leak Detector J 41425 A/C Line Repair Kit J 41447 R-134A A/C Tracer Dye - Box of 24 J 42220 Universal 12V Leak Detection Lamp J 43181 Heater Line Q.C. Release Tool J 43600 ACR 2000 Air Conditioning Service Center J 43872 Fluorescent Dye Cleaner J 45037 A/C PAG Oil Injector (Non-HP2) J 45268 Flush Adapter Kit J 46297 A/C Dye Injector Kit J 46297-12 Replacement Dye Cartridges

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

See also:
• Diagnostic System Check - Vehicle
• Symptoms - HVAC Systems - Manual
• Symptoms - HVAC Systems - Automatic
• Moving Parts and Hot Surfaces Warning
• Cooling System Description and Operation
• Fan Clutch Diagnosis
• Engine Fails To Reach Normal Operating Temperature
• Air Conditioning Compressor Malfunction
• Air Conditioning Compressor Malfunction
• Drive Belt Falls Off and Excessive Wear Diagnosis
• Drive Belt Tensioner Diagnosis
• Air Conditioning Compressor Belt Replacement (V8)
• Vibration Analysis - Engine
• Instrument Panel Carrier Replacement
• Loss of Coolant
• Oil Leak Diagnosis
• Power Steering Fluid Leaks
• Fastener Caution
• Drive Belt Replacement
• Air Cleaner Resonator Outlet Duct Replacement
• Lifting and Jacking the Vehicle
• Engine Shield Replacement
• Air Conditioning Compressor Control Module Programming and Setup
• Front End Upper Tie Bar Replacement
• Battery Replacement
• Instrument Panel Service Positioning (without SLT)
• Refrigerant Recovery and Recharging (Non-HP2)
• Air Conditioning (A/C) Diagnostics - Pressure Zone A
• Air Conditioning (A/C) System Performance Test (Diesel Engine)
• Refrigerant System Capacities (Non-HP2)
• Heating Performance Diagnostic
• Air Conditioning Compressor Oil Diagnosis
• Air Conditioning Clutch Drive Plate Adjustment