Engine Cooling System: Removal & Installation Chevrolet Silverado 2500

Installation Procedure

1. Install the surge tank.
2. Install the bolt to the surge tank. Tighten the bolt to 9 N.m (80 lb in).
3. Install the nut to the surge tank. Tighten the nut to 9 N.m (80 lb in).
4. Install the surge tank outlet hose (2) to the surge tank.
5. Position the surge tank outlet hose clamp to the surge tank.
6. Install the surge tank inlet hose (1) to the surge tank.
7. Position the surge tank inlet hose clamp to the surge tank.
8. Connect the coolant level sensor electrical connector (3).
9. Install the surge tank overflow hose.
10. Install the air cleaner assembly.
11. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 54

Scheme 55

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Reposition the surge tank inlet hose clamp from the radiator.
3. Remove the surge tank inlet hose from the radiator.
4. Reposition the surge tank inlet hose clamp from the surge tank.
5. Remove the surge tank inlet hose (1) from the surge tank.

1. Install the surge tank inlet hose (1) to the surge tank.
2. Position the surge tank inlet hose clamp to the surge tank.
3. Install the surge tank inlet hose to the radiator.
4. Position the surge tank inlet hose clamp to the radiator.
5. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 56

Scheme 57

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Separate the MAF/IAT sensor assembly and the air inlet tube by loosening the hose clamp.
3. Disconnect the PCV hose from the air cleaner outlet duct.
4. Remove the air inlet tube and resonator retaining wing nut.
5. Remove the air inlet tube and resonator from the throttle body by pivoting the air inlet tube and resonator upward until the hinge clip releases from the lip on the throttle body.
6. Remove the radiator inlet hose from the support.
7. Remove the radiator inlet hose from the radiator.
8. Remove the radiator inlet hose from the thermostat housing.
9. Remove the radiator inlet hose.

1. Install the radiator inlet hose to the thermostat housing.
2. Install the radiator inlet hose to the radiator.
3. Install the radiator inlet hose to the support.
4. Align the hinge clip with the lip on the throttle body. Install the air inlet tube and resonator to the throttle body by pivoting the air inlet tube and resonator downward until the mounting stud is through the hole in the air inlet tube.
5. Install the resonator retaining wing nut.
6. Connect the PCV hose to the air cleaner outlet duct.
7. Connect the MAF/IAT sensor assembly harness connector.
8. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 58

Scheme 59

Scheme 60

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet hose.
4. Remove the air cleaner outlet duct.
5. If necessary, remove the engine sight shield.
6. Remove the radiator vent inlet hose from the radiator inlet hose clips.
7. Reposition the inlet hose clamp at the radiator.
8. Remove the inlet hose clip from the fan shroud.
9. Remove the inlet hose from the radiator.
10. Reposition the inlet hose clamp at the water pump.
11. Remove the inlet hose from the water pump.

1. Install the inlet hose to the water pump.
2. Position the inlet hose clamp at the water pump.
3. Install the inlet hose to the radiator.
4. Position the inlet hose clamp at the radiator.
5. Install the inlet hose clip to the fan shroud.
6. Install the radiator vent inlet hose to the radiator inlet hose clips.
7. If necessary, install the engine sight shield. Important: Align the arrow at the throttle body end of the duct with the throttle body attaching stud.
8. Install the air cleaner outlet duct.
9. Install the radiator inlet hose clip to the outlet duct.
10. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten the air cleaner outlet duct clamp screws to 7 N.m (62 lb in).
11. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 61

1. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Move the hose clamps back on the radiator inlet hose.
3. Remove the radiator inlet hose from the radiator.
4. Remove the radiator inlet hose from the water outlet tube.

1. Install the radiator inlet hose to the water outlet tube.
2. Install the radiator inlet hose to the radiator.
3. Install the hose clamps on the radiator outlet hose.
4. Fill the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Removal Procedure

Important: Most truck models use a spring-type hose clamp at the hose connections. When using this type of clamp, install the radiator hoses on dry, non-painted surfaces in order to ensure proper sealing.

Reusing the spring-type clamps on aftermarket hoses is not recommended.

Scheme 62

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Reposition the inlet hose clamp at the radiator.
3. Remove the inlet hose from the radiator.
4. Reposition the inlet hose clamp at the water crossover.
5. Remove the inlet hose from the water crossover.

1. Install the inlet hose to the water crossover.
2. Position the inlet hose clamp at the water crossover.
3. Install the inlet hose to the radiator.
4. Position the inlet hose clamp at the radiator.
5. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 63

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Scheme 65

1. Separate the MAF/IAT sensor assembly and the air inlet tube by loosening the hose clamp.
2. Disconnect the PCV hose from the air cleaner outlet duct.
3. Remove the air inlet tube and resonator retaining wing nut.
4. Remove the air inlet tube and resonator from the throttle body by pivoting the air inlet tube and resonator upward until the hinge clip releases from the lip on the throttle body.
5. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
6. Remove the radiator outlet hose from the surge tank.
7. Remove the radiator outlet hose from the water pump.
8. Remove the radiator outlet hose from the radiator.
9. Remove the radiator outlet hose.

1. Install the radiator outlet hose to the radiator.
2. Install the radiator outlet hose to the water pump.
3. Install the radiator outlet hose to the surge tank.
4. Align the hinge clip with the lip on the throttle body. Install the air inlet tube and resonator to the throttle body by pivoting the air inlet tube and resonator downward until the mounting stud is through the hole in the air inlet tube.
5. Install the resonator retaining wing nut.
6. Connect the PCV hose to the air cleaner outlet duct.
7. Connect the MAF/IAT sensor assembly harness connector.
8. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 66

Scheme 67

Scheme 68

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet duct.
4. Remove the air cleaner outlet duct.
5. Reposition the outlet hose clamp at the water pump.
6. Remove the outlet hose from the water pump.
7. Reposition the outlet hose clamp at the radiator.
8. Remove the outlet hose from the radiator.

1. Install the outlet hose to the radiator.
2. Position the outlet hose clamp at the radiator.
3. Install the outlet hose to the water pump.
4. Position the outlet hose clamp at the water pump. Important: Align the arrow at the throttle body end of the duct with the throttle body attaching stud.
5. Install the air cleaner outlet duct.
6. Install the radiator inlet hose clip to the outlet duct.
7. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten the air cleaner outlet duct clamp screws to 7 N.m (62 lb in).
8. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 69

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Scheme 71

1. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Remove the upper and lower fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) , «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) or «Fan Shroud Replacement - Lower»(ref-176275-S30244706742005050500000) .
3. Remove the surge tank outlet hose (2) from the surge tank.
4. Remove the radiator outlet hose from the water pump.
5. Remove the heater outlet hose from the radiator outlet hose.
6. Remove the radiator outlet hose from the radiator.
7. Remove the radiator outlet hose clip retainers from the brackets.
8. Remove the radiator outlet hose from the vehicle.

1. Install the radiator outlet hose to the vehicle.
2. Install the radiator outlet hose and clamp to the radiator. Ensure the hose is positioned properly in order to prevent interference with the fan shroud.
3. Install the radiator outlet hose clip retainers to the brackets.
4. Install the surge tank outlet hose (2) to the surge tank.
5. Install the radiator outlet hose and clamp to the water pump.
6. Install the heater outlet hose to the radiator outlet hose.
7. Install the upper and lower fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) , «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) or «Fan Shroud Replacement - Lower»(ref-176275-S30244706742005050500000) .
8. Fill the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Important: Most truck models use a spring-type hose clamp at the hose connections. When using this type of clamp, install the radiator hoses on dry, non-painted surfaces in order to ensure proper sealing.

Reusing the spring-type clamps on aftermarket hoses is not recommended.

Scheme 72

Scheme 73

Scheme 74

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Reposition the outlet hose clamp at the radiator.
3. Remove the radiator outlet hose from the radiator.
4. Reposition the surge tank outlet hose clamp at the surge tank.
5. Remove the surge tank outlet hose (2) from the surge tank.
6. Reposition the outlet hose clamp the water pump.
7. Remove the outlet hose from the water pump.

1. Install the outlet hose from the water pump.
2. Position the outlet hose clamp the water pump.
3. Install the surge tank outlet hose (2) from the surge tank.
4. Position the surge tank outlet hose clamp at the surge tank.
5. Install the radiator outlet hose to the radiator.
6. Position the outlet hose clamp at the radiator.
7. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 75

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Reposition the vent inlet hose clamp from the radiator.
3. Remove the vent inlet hose from the radiator.
4. Reposition the vent inlet hose clamp from the surge tank.
5. Remove the vent inlet hose from the surge tank.

1. Install the vent inlet hose to the surge tank.
2. Reposition the vent inlet hose clamp to the surge tank.
3. Install the vent inlet hose to the radiator.
4. Reposition the vent inlet hose clamp to the radiator.
5. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

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

Scheme 76

Scheme 77

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Scheme 80

1. Disengage the plastic caps from the quick connect fittings. Pull the caps back along the pipe.
2. Hold one leg of the retaining clip.
3. Using a small pick-type tool or bent screwdriver, gently pry the other end of the retaining clip from the quick connect fitting.
4. Rotate the retaining clip out of the quick connect fitting. Remove the retaining clip completely.
5. Discard the OLD retaining clip.
6. If equipped with a 6.0L engine, perform the following: 6.1. Open the oil cooler hose clip located on the lower fan shroud. 6.2. Remove the oil cooler hoses from the clip. 6.3. Gently, pull the oil cooler pipe fittings straight out from the radiator quick connect fittings. 6.4. Raise and suitably support the vehicle.
7. If equipped with a 8.1L engine, perform the following: 7.1. Remove the oil cooler hoses from the clip. 7.2. Gently, pull the oil cooler pipe fittings straight out from the radiator quick connect fittings. 7.3. Raise and suitably support the vehicle.
8. If equipped, remove the engine shield bolts.
9. Remove the engine shield.
10. If equipped with the a 6.0L engine, perform the following: 10.1. Remove the oil cooler hose bracket bolt (1). 10.2. Remove the oil cooler hose adapter bolts (2). 10.3. Remove the oil cooler hose assembly and gasket. Discard the gasket. 10.4. Inspect the fittings, connectors and cooler hoses for damage or distortion.
11. If equipped with a 8.1L engine, perform the following: 11.1. Remove the oil cooler hose bracket bolt. 11.2. Disconnect the quick connect fittings (1) at the engine. 11.3. Remove the oil cooler hose assembly. Discard the gasket. 11.4. Inspect the fittings, connectors and cooler hoses for damage or distortion.

Important: A distinct snap should be heard when assembling tube ends of the hose assembly to quick connectors. To ensure tube is fully inserted into the connector, check by giving tube a forceful pull.

Scheme 81

Scheme 82

1. If equipped with a 8.1L engine, perform the following: 1.1. Remove the oil cooler hose assembly. 1.2. Connect the quick connect fittings (1) at the engine. 1.3. Install the oil cooler hose bracket bolt. Tighten the bolt to 50 N.m (37 lb ft).
2. If equipped with a 6.0L engine, perform the following: 2.1. Install the oil cooler hose assembly and a new gasket. 2.2. Install the oil cooler hose adapter bolts (2). Tighten the bolts to 12 N.m (106 lb in). 2.3. Install the oil cooler hose bracket bolt (1). Tighten the bolt to 25 N.m (18 lb ft).
3. If equipped, install the engine shield.
4. Install the engine shield bolts. Tighten the bolts to 20 N.m (15 lb ft).
5. Do not install the new retaining clip onto the fitting by pushing on the clip. Important: Failure to properly install the retaining clip could cause the cooler line to come loose and cause damage to the engine.
6. Install the NEW retaining clip into the quick connect fitting by using your thumb and forefinger. Insert the new retaining clip into one of the three fitting recesses. Ensure that the retaining clip is engaged in all 3 slots.
7. With one end of the retaining clip engaged in the connector fitting slot, use your thumb in order to rotate the retaining clip around the connector fitting, until the retaining clip snaps into place.
8. Ensure that the 3 retaining clip ears are seen from inside the fitting and that the retaining clip moves freely in the fitting slots.
9. Install a new retaining clip into the remaining quick connect fitting.
10. If equipped with a 6.0L engine, perform the following: 10.1. Install the oil cooler hoses to the hose clip on the fan shroud. 10.2. Snap the oil cooler hose clip shut. Important: Ensure the oil cooler line being installed has a plastic cap on the end that connects to the quick connect fitting. If no plastic cap exists, or the plastic cap is damaged, obtain a new cap. Install the cap on to the cooler line prior to cooler line installation. Do not use the plastic cap in order to install the cooler line into the fitting.
11. If equipped with a 8.1L engine, perform the following: 11.1. Install the oil cooler hoses to the clip. 11.2. Install the oil cooler lines to the radiator. Install the cooler line straight into the quick connect fitting. Insert the cooler line end into the quick connect fitting until a click is either heard or felt. 11.3. Pull back sharply on the cooler line in order to ensure that the cooler line is installed in the quick connect fitting. Important: Do not manually depress the retaining clip when installing the plastic cap.
12. Snap the plastic cap onto the quick connect fitting.
13. Ensure that the plastic cap is fully seated against the fitting.
14. Ensure that no gap is present between the cap and the fitting.
15. Ensure that the yellow identification band on the tube is hidden within the quick connect fitting. A hidden yellow identification band indicates proper joint seating.
16. Run the engine. Inspect the engine oil cooling system for leaks.
17. Inspect the engine oil level. Add oil if necessary.

Fan Replacement

Tools Required

1. J 41240 Fan Clutch Remover and Installer
2. J 41240-5A Fan Clutch Wrench

Scheme 83

Scheme 84

1. Remove the upper fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) or «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) .
2. If equipped with a 4.3L, 4.8L, 5.3L, 6.0L or 8.1L engine, install the J 41240 to the fan clutch.
3. If equipped with a 6.6L, engine, install the J41240-5A to the fan clutch.
4. Remove the fan assembly.
5. Lay the fan blade face down on a workbench.
6. Remove the fan clutch bolts from the rear of the fan blade.
7. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts. Tighten the fan clutch bolts to 23 N.m (17 lb ft).
3. Install the fan assembly.
4. If equipped with a 6.6L, engine, install the J41240-5A to the fan clutch.
5. If equipped with a 4.3L, 4.8L, 5.3L, 6.0L or 8.1L engine, install the J 41240 to the fan clutch. Tighten the fan clutch nut to 56 N.m (41 lb ft).
6. Install the upper fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) or «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) .

Fan Clutch Replacement

Tools Required

1. J 41240 Fan Clutch Remover and Installer
2. J41240-5A Fan Clutch Wrench

1. Remove the upper fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) or «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) .
2. If equipped with a 4.3L, 4.8L, 5.3L, 6.0L or 8.1L engine, install the J 41240 to the fan clutch.
3. If equipped with a 6.6L engine, install the J41240-5A to the fan clutch.
4. Remove the fan assembly.
5. Remove the fan clutch bolts from the rear of the fan blade.
6. Separate the fan clutch from the fan blade.

1. Install the fan clutch bolts from the rear of the fan blade.
2. Install the fan clutch bolts. Tighten the fan clutch bolts to 23 N.m (17 lb ft).
3. Install the fan assembly.
4. If equipped with a 6.6L engine, install the J41240-5A to the fan clutch.
5. If equipped with a 4.3L, 4.8L, 5.3L, 6.0L or 8.1L engine, install the J 41240 to the fan clutch. Tighten the fan clutch nut to 56 N.m (41 lb ft).
6. Install the upper fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) or «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) .

Scheme 85

1. Remove the fan clutch. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
2. Disconnect the camshaft position sensor connector.
3. Remove the 3 retaining bolts and 2 nuts for the cooling fan pulley.
4. Remove the cooling fan pulley assembly.
5. Remove the cooling fan pulley insulator pad.

1. Install the cooling fan pulley insulator pad.
2. Install the cooling fan pulley assembly.
3. Install the cooling fan pulley assembly bolts and nuts. Tighten the cooling fan pulley bolts and 2 nuts to 46 N.m (34 lb ft).
4. Connect the camshaft position sensor connector.
5. Install the fan clutch. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .

Scheme 86

Scheme 87

1. Loosen the outlet duct clamp at the upper intake manifold cover.
2. Remove the upper intake manifold cover from the outlet duct.
3. Remove the upper intake manifold cover.
4. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
5. Disconnect the turbocharger coolant hose from the turbocharger bypass valve.
6. Remove the turbocharger bypass valve and sealing washer from the water outlet tube.

1. Install the turbocharger bypass valve and sealing washer to the water outlet tube. Tighten the turbocharger bypass valve to 60 N.m (44 lb ft).
2. Connect the turbocharger coolant hose to the turbocharger bypass valve.
3. Install the upper intake manifold cover.
4. Install the upper intake manifold cover to the outlet duct.
5. Tighten the outlet duct clamp at the upper intake manifold cover. Tighten the clamp to 6 N.m (53 lb in).
6. Fill the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Turbocharger Coolant Hoses/Pipes Replacement (6.6L Engine)

Tools Required

J 43181 Heater Line Quick Connect Release Tool

Scheme 88

Scheme 89

Scheme 90

Scheme 91

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Scheme 94

1. Loosen the outlet duct clamp at the upper intake manifold cover.
2. Remove the upper intake manifold cover from the outlet duct.
3. Remove the upper intake manifold cover.
4. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
5. Disconnect both battery negative cables. Important: After removing the charged air cooler ducts, cover the turbocharger openings and the ducts with tape to prevent entry of objects.
6. Loosen the outlet duct clamps at the turbocharger and the mass air flow/intake air temperature (MAF/IAT) sensor.
7. Remove the outlet duct from the turbocharger and MAF/IAT sensor.
8. Loosen both of the charged air cooler outlet duct to intake hose clamps. Important: Do not use a screw driver or other tool to pry the hose loose. The hose can be torn or damage. Loosen the hose by twisting.
9. Remove the charged air cooler duct to intake hose.
10. Remove the nut retaining the positive cable to the generator.
11. Remove the positive cable from the generator.
12. Disconnect the generator electrical connector.
13. Remove the ribbed idler pulley from the generator bracket.
14. Remove the generator mounting bracket and secure to the side. The generator does not require removal. The drive belt tensioner does not require removal.
15. Disconnect the wiring harness connector to the fuel injection control module.
16. Remove the fuel lines to the fuel injection control module.
17. Use the J 43181 in order to disconnect the inlet heater hose from the heater core inlet.
18. Remove the fuel injection control module wiring harness conduit from the heater pipe.
19. Remove the bolt retaining the heater pipe to the fuel filter assembly.
20. Remove the bolt retaining the heater pipe to the thermostat housing.
21. Remove the heater pipe with O-ring seal from the thermostat housing.
22. Remove the bolt retaining the turbocharger outlet coolant pipe to the turbocharger coolant pipe bracket.
23. Remove the hose and clamp from the turbocharger outlet coolant pipe to thermostat bypass pipe.
24. Disconnect the turbocharger outlet coolant hose from the turbocharger.
25. Remove the nut retaining the turbocharger outlet coolant pipe.
26. Remove the coolant pipe from the engine.
27. Disconnect the turbocharger inlet coolant hose from the turbocharger coolant bypass valve.
28. Disconnect the turbocharger inlet coolant hose from the turbocharger.

Scheme 95

1. Connect the turbocharger inlet coolant hose and clamp to the turbocharger coolant bypass valve.
2. Connect the turbocharger inlet coolant hose and clamp to the turbocharger.
3. Install the turbocharger outlet coolant pipe to the engine.
4. Install the nut retaining the turbocharger outlet coolant pipe. Tighten the turbocharger outlet coolant pipe nut to 9 N.m (80 lb in).
5. Connect the turbocharger outlet coolant hose and clamps to the turbocharger and the coolant pipe.
6. Install the hose and clamp to the turbocharger outlet coolant pipe to thermostat bypass pipe.
7. Install the bolt retaining the turbocharger outlet coolant pipe to the pipe bracket. Tighten the turbocharger outlet coolant pipe bracket bolt to 21 N.m (15 lb ft).
8. Install a new O-ring seal to the heater pipe.
9. Install the heater pipe to the thermostat housing.
10. Install the bolt retaining the heater pipe to the thermostat housing. Tighten the heater pipe bolt to 21 N.m (15 lb ft).
11. Install the bolt retaining the heater pipe to the fuel filter assembly. Tighten the heater pipe bracket bolt to 21 N.m (15 lb ft).
12. Connect the inlet heater hose to the heater inlet.
13. Install the fuel injection control module wiring harness conduit to the heater pipe.
14. Install the generator mounting bracket and bolts. Tighten the generator mounting bracket bolts to 50 N.m (37 lb ft).
15. Install the ribbed idler pulley and bolt. Tighten the idler pulley bolt to 43 N.m (32 lb ft).
16. Install the fuel lines to the fuel injection control module.
17. Connect the wiring harness connector to the fuel injection control module.
18. Install the generator positive cable and the retaining nut to the generator. Tighten the generator positive cable nut to 9 N.m (80 lb in).
19. Connect the generator electrical connector.
20. Install the charged air cooler outlet duct to intake hose. The hose is marked DUCT which connects to the charged air cooler outlet duct. The hose is marked ENG which connects to the turbocharger. Align the marks on the hose with the alignment marks on the pipe and duct.
21. Position the clamps as shown for proper clearance. Tighten the clamps to 6 N.m (53 lb in).
22. Install the outlet duct to the turbocharger.
23. Align the outlet duct alignment indicator (1) to the turbocharger alignment indicator (2).
24. Install the outlet duct to the MAF/IAT sensor.
25. Tighten the outlet duct clamps at the turbocharger and the MAF/IAT sensor. Tighten the clamps to 6 N.m (53 lb in).
26. Install the upper intake manifold cover.
27. Install the upper intake manifold cover to the outlet duct.
28. Tighten the outlet duct clamp at the upper intake manifold cover. Tighten the clamp to 6 N.m (53 lb in).
29. Fill the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
30. Connect both battery negative cables.

Scheme 96

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Scheme 98

1. Loosen the outlet duct clamp at the upper intake manifold cover.
2. Remove the upper intake manifold cover from the outlet duct.
3. Remove the upper intake manifold cover.
4. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
5. Remove the radiator inlet hose from the water outlet tube.
6. Remove the bolt and wiring harness bracket at the thermostat housing.
7. Disconnect the turbocharger coolant hose from the turbocharger bypass valve.
8. Remove the turbocharger bypass valve and sealing washer from the water outlet tube.
9. Remove the 2 bolts retaining the water outlet tube to the left valve rocker arm cover.
10. Remove the bolt retaining the water outlet tube to the thermostat housing.
11. Remove the water outlet tube.
12. Remove and discard the O-ring seal.

1. Install a new O-ring seal on the water outlet tube.
2. Lightly lubricate the O-ring seal with coolant.
3. Install the water outlet tube.
4. Install the bolt retaining the water outlet tube to the thermostat housing. Tighten the water outlet tube to thermostat housing bolt to 21 N.m (15 lb ft).
5. Install the 2 bolts retaining the water outlet tube to the valve rocker arm cover. Tighten the water outlet tube to valve rocker arm cover bolts to 21 N.m (15 lb ft).
6. Install the turbocharger bypass valve and sealing washer to the water outlet tube. Tighten the turbocharger bypass valve to 60 N.m (44 lb ft).
7. Connect the turbocharger coolant hose to the turbocharger bypass valve.
8. Install the bolt and wiring harness bracket to the thermostat housing. Tighten the wiring harness bracket bolt to 8 N.m (71 lb in).
9. Install the radiator inlet hose to the water outlet tube.
10. Fill the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
11. Install the upper intake manifold cover.
12. Install the upper intake manifold cover to the outlet duct.
13. Tighten the outlet duct clamp at the upper intake manifold cover. Tighten the clamp to 6 N.m (53 lb in).

Important: The thermostat is not serviceable separately. The water pump inlet and thermostat must be replaced as an assembly.

Scheme 99

1. Remove the radiator outlet hose.
2. Remove the water pump inlet bolts.
3. Remove the water pump inlet and thermostat from the water pump.

1. Install the thermostat and water pump inlet to the water pump.
2. Install the water pump inlet bolts. Tighten the water pump inlet bolts to 15 N.m (11 lb ft).
3. Install the radiator outlet hose.

Scheme 100

Scheme 101

Scheme 102

Scheme 103

Scheme 104

Scheme 105

Scheme 106

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Loosen the air cleaner outlet duct clamp at the mass airflow/intake air temperature (MAF/IAT) sensor.
3. Remove the positive crankcase ventilation (PCV) hose.
4. Remove the air cleaner adapter nut.
5. In order to remove the air cleaner outlet duct, pivot the duct upward until the hinge clip releases from the lip on the throttle body.
6. Reposition the inlet hose clamp at the water outlet.
7. Remove the inlet hose from the water outlet.
8. Remove the water outlet studs.
9. Remove the water outlet.
10. Remove the thermostat.
11. Clean the sealing surface of the water outlet.
12. Clean the sealing surface of the intake manifold.
13. Remove and discard the O-ring seal.

1. Install a NEW O-ring seal to the thermostat.
2. Install the thermostat.
3. Install the water outlet.
4. Install the water outlet studs. Tighten the water outlet studs to 25 N.m (18 lb ft).
5. Install the inlet hose to the water outlet.
6. Position the inlet hose clamp at the water outlet.
7. Align the hinge clip with the lip on the throttle body. In order to install the air cleaner outlet duct, pivot the air cleaner outlet duct downward until the mounting stud is through the hole.
8. Install the air cleaner adapter nut.
9. Install the PCV hose.
10. Tighten the air cleaner outlet duct clamp at the MAF/IAT sensor.
11. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
12. Inspect the cooling system for leaks.

Scheme 107

1. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Remove the water outlet tube. Refer to «Water Outlet Tube Replacement (6.6L Engine)»(ref-176275-S12964047272005050500000) .
3. Remove the bolt for the fuel line bracket.
4. Remove the 4 bolts retaining the thermostat housing cover.
5. Remove the 2 thermostats with the seals.

1. Install the thermostat (3).
2. Install the water outlet (1).
3. Install the water outlet bolts (2). Tighten the water outlet bolts to 30 N.m (22 lb ft).
4. Install the inlet hose to the water outlet.
5. Position the inlet hose clamp at the water outlet.
6. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 108

Scheme 109

Scheme 110

Scheme 111

1. Loosen the outlet duct clamp at the upper intake manifold cover.
2. Remove the upper intake manifold cover from the outlet duct.
3. Remove the upper intake manifold cover.
4. Disconnect the battery negative cable.
5. Drain the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
6. Remove the upper fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) or «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) .
7. Remove the drive belt.
8. Disconnect the A/C compressor clutch electrical connector.
9. Disconnect the A/C cut out switch electrical connector.
10. Remove the A/C compressor mounting bolts.
11. Move the A/C compressor with the hoses attached to the right side of the engine compartment.
12. Remove the nut retaining the generator positive cable to the generator.
13. Remove the positive cable from the generator.
14. Remove the clip holding the positive cable to the engine front cover.
15. Remove the bolt retaining the battery positive cable junction block to the power steering pump.
16. Move the generator positive cable and the junction block bracket aside.
17. Disconnect the generator electrical connector.
18. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
19. Remove the power steering pump mounting bracket and secure to the side. Do not remove the power steering pump from the bracket. The hoses and battery cables can remain on the power steering pump.
20. Remove the bolts retaining the fuel bleed valve and PCV oil separator bracket from the generator mounting bracket.
21. Remove the heater outlet hose bracket bolt from the generator bracket.
22. Remove the ribbed idler pulley.
23. Remove the generator mounting bracket and secure to the side. The generator does not require removal. The drive belt tensioner does not require removal.
24. Remove the oil fill tube.
25. Remove the water outlet tube. Refer to «Water Outlet Tube Replacement (6.6L Engine)»(ref-176275-S12964047272005050500000) .
26. Remove the bolt retaining the heater pipe to the fuel filter assembly.
27. Remove the bolt retaining the heater pipe to the thermostat housing crossover.
28. Remove the heater pipe with O-ring seal from the crossover.
29. Remove the hose and clamp from the turbocharger outlet coolant pipe to thermostat bypass pipe.
30. Remove the fuel line bracket from the thermostat housing crossover.
31. Remove the cooling fan pulley. Refer to «Cooling Fan Pulley Replacement (6.6L Engine)»(ref-176275-S27076832452005050500000) .
32. Remove the 2 thermostat housing crossover bolts and 2 nuts from the left cylinder head.
33. Remove the 2 thermostat housing crossover bolts and 2 nuts from the right cylinder head.
34. Remove the bypass pipe to water pump bolts.
35. Remove the thermostat housing crossover with the bypass pipe.
36. Remove the bypass pipe to water pump O-ring.
37. Remove the bypass pipe from the thermostat housing crossover.
38. Remove the O-ring from the bypass pipe.

1. Install a new O-ring to the bypass pipe. Lubricate the O-ring with coolant.
2. Install the bypass pipe to the thermostat housing crossover.
3. Install new thermostat crossover gaskets.
4. Install a new O-ring for the bypass pipe to the water pump.
5. Install the thermostat crossover with the bypass pipe.
6. Install the bypass pipe to water pump bolts. Tighten the bypass pipe to water pump bolts to 21 N.m (15 lb ft).
7. Install the thermostat crossover bolts and nuts. Tighten the thermostat crossover bolts and nuts to 21 N.m (15 lb ft).
8. Install the fuel line bracket and bolt. Tighten the fuel line bracket bolt to 21 N.m (15 lb ft).
9. Install the hose and clamp from the turbocharger outlet coolant pipe to thermostat bypass pipe.
10. Install the cooling fan pulley.
11. Install a new O-ring seal to the heater pipe.
12. Install the heater pipe to the thermostat housing crossover.
13. Install the bolt retaining the heater pipe to the thermostat housing crossover. Tighten the heater pipe bolt to 21 N.m (15 lb ft).
14. Install the bolt retaining the heater pipe to the fuel filter assembly. Tighten the heater pipe bracket bolt to 21 N.m (15 lb ft).
15. Install the generator mounting bracket and bolts. Tighten the generator mounting bracket bolts to 50 N.m (37 lb ft).
16. Install the ribbed idler pulley and the bolt. Tighten the idler puller bolt to 43 N.m (32 lb ft).
17. Install the heater outlet hose bracket bolt. Tighten the bracket bolt to 21 N.m (15 lb ft).
18. Install the nuts retaining the fuel bleed valve and PCV oil separator bracket from the generator mounting bracket. Tighten the bracket nuts to 25 N.m (18 lb ft).
19. Install the power steering pump mounting bracket and bolts. Tighten the power steering pump mounting bracket bolts to 46 N.m (34 lb ft).
20. Install the water outlet tube.
21. Position the generator positive cable.
22. Install the generator positive cable in the clip on the engine front cover.
23. Install the generator positive cable and the retaining nut to the generator. Tighten the generator positive cable nut to 9 N.m (80 lb in).
24. Install the battery positive cable junction block bracket and bolt to the power steering pump. Tighten the junction block bracket bolt to 9 N.m (80 lb in).
25. Connect the generator electrical connector.
26. Position the A/C compressor.
27. Install the A/C compressor mounting bolts. Tighten the A/C compressor mounting bolts to 50 N.m (37 lb ft).
28. Connect the A/C cut out switch electrical connector.
29. Connect the A/C clutch electrical connector.
30. Install the drive belt.
31. Install the upper fan shroud. Refer to «Fan Shroud Replacement - Upper (W/O M74)»(ref-176275-S39210327492005050500000) or «Fan Shroud Replacement - Upper (W/M74)»(ref-176275-S37336424892005050500000) .
32. Fill the engine coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
33. Connect the battery negative cable.
34. Install the upper intake manifold cover.
35. Install the upper intake manifold cover to the outlet duct.
36. Tighten the outlet duct clamp at the upper intake manifold cover. Tighten the clamp to 6 N.m (53 lb in).

Scheme 112

Scheme 113

Scheme 114

Scheme 115

Scheme 116

Scheme 117

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Remove the drive belt tensioner.
3. Reposition the inlet hose clamp at the water crossover.
4. Remove the inlet hose from the water crossover.
5. Reposition the heater inlet hose clamp at the water crossover.
6. Remove the heater inlet hose from the water crossover.
7. Reposition the bypass hose clamps at the water crossover and water pump.
8. Remove the bypass hose.
9. Remove the generator.
10. Remove the power steering pump.
11. Remove the generator bracket bolts and nut.
12. Remove the generator bracket stud.
13. Remove the generator bracket.
14. Remove the water crossover bolts.
15. Remove the water crossover.
16. Remove and discard the water crossover gaskets.
17. If replacing the water crossover remove the following: 17.1. Water outlet bolts (2) 17.2. Water outlet (1) 17.3. Thermostat (3)

1. If replacing the water crossover install the following: 1.1. Thermostat (3) 1.2. Water outlet (1) 1.3. Water outlet bolts (2) Tighten the water outlet bolts to 30 N.m (22 lb ft).
2. Install NEW water crossover gaskets.
3. Install the water crossover.
4. Install the water crossover bolts. Tighten the water crossover bolts to 50 N.m (37 lb ft).
5. Install the generator bracket.
6. Install the generator bracket stud. Tighten the generator bracket stud to 20 N.m (15 lb ft).
7. Install the generator bracket bolts and nut. Tighten the generator bracket bolts and nut to 50 N.m (37 lb ft).
8. Install the power steering pump.
9. Install the generator.
10. Install the bypass hose.
11. Position the bypass hose clamps at the water crossover and water pump.
12. Install the heater inlet hose to the water crossover.
13. Position the heater inlet hose clamp at the water crossover.
14. Install the inlet hose to the water crossover.
15. Position the inlet hose clamp at the water crossover.
16. Install the drive belt tensioner.
17. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 118

Scheme 119

Scheme 120

Scheme 121

1. Remove the intake manifold.
2. Remove the coolant air bleed pipe studs (1).
3. Remove the coolant air bleed pipe (2) with gaskets (3).
4. Remove the coolant air bleed pipe cover bolts (1) and covers (2).
5. Remove the gaskets from the coolant air bleed pipe and covers.
6. Discard the gaskets.
7. Remove the coolant air bleed hose (1) from the pipe (2).

1. Install the coolant air bleed hose (1) onto the pipe (2). Important: Install the gaskets properly onto the pipe and covers. Position the O-ring seal onto the nipple portion of the pipe.
2. Install the gaskets onto the coolant air bleed pipe and covers.
3. Install the coolant air bleed pipe (2) and gaskets (3) onto the cylinder heads.
4. Install the coolant air bleed pipe studs (1). Tighten the coolant air bleed pipe studs to 12 N.m (106 lb in).
5. Install the coolant air bleed pipe covers (2) and bolts (1). Tighten the coolant air bleed pipe cover bolts to 12 N.m (106 lb in).
6. Install the intake manifold.

Scheme 122

Scheme 123

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

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

Scheme 124

1. Remove the thermostat housing crossover with the thermostat bypass pipe attached. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(ref-176275-S23281057122005050500000) .
2. Remove the thermostat bypass pipe and O-ring seal from the water crossover.
3. Remove and discard the O-ring seal.
4. Clean the sealing surfaces of the bypass pipe.
5. Clean the water pump and the thermostat housing crossover sealing surfaces.

1. Install a new O-ring seal on the thermostat bypass pipe.
2. Lightly lubricate the O-ring seal with coolant.
3. Install a new O-ring seal for the bypass pipe to the water pump.
4. Install the bypass pipe in the thermostat housing crossover.
5. Install the thermostat housing crossover with the thermostat bypass pipe attached. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(ref-176275-S23281057122005050500000) .

Water Pump Replacement (4.3L Engine)

Tools Required

J 41240 Fan Clutch Remover and Installer

Scheme 125

Scheme 126

Scheme 127

Scheme 128

Scheme 129

Scheme 130

Scheme 131

1. Loosen the air cleaner outlet duct clamp at the mass airflow/intake air temperature sensor.
2. Remove the positive crankcase ventilation (PCV) hose.
3. Remove the air cleaner adapter nut.
4. In order to remove the air cleaner outlet duct, pivot the duct upward until the hinge clip release from the lip on the throttle body.
5. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
6. Remove the cooling fan. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
7. Remove the drive belt.
8. Reposition the radiator outlet hose clamps at the surge tank and water pump.
9. Remove the radiator outlet hose from the surge tank.
10. Remove the radiator outlet hose from the water pump.
11. Reposition the water pump inlet hose clamps.
12. Remove the water pump inlet hose.
13. Using J 41240 to hold the water pump pulley, remove the water pump pulley bolts.
14. Remove the water pump bolts.
15. Remove the water pump.
16. Remove and discard the water pump gaskets.
17. Clean and inspect the water pump, if necessary.

1. If reusing the fasteners, apply sealant GM P/N United States 12346004, GM P/N Canada 10953480, or equivalent to the threads of the water pump bolts.
2. Install NEW water pump gaskets and the water pump.
3. Install the water pump bolts. Tighten the water pump bolts to 45 N.m (33 lb ft).
4. Using J 41240 to hold the water pump pulley, install the water pump pulley bolts. Tighten the water pump pulley bolts to 25 N.m (18 lb ft). Important: After assembly, the hose clamp tangs (water pump end) must point forward and the upper tang should be level with the outside diameter of the water pump inlet hose.
5. Install the water pump inlet hose.
6. Position the water pump inlet hose clamps.
7. Install the radiator outlet hose to the water pump.
8. Install the radiator outlet hose to the surge tank.
9. Position the radiator outlet hose clamps at the surge tank and water pump.
10. Install the drive belt.
11. Install the cooling fan. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
12. Align the hinge clip with the lip on the throttle body. In order to install the air cleaner outlet duct, pivot the air cleaner outlet duct downward until the mounting stud is through the hole.
13. Install the air cleaner adapter nut.
14. Install the PCV hose.
15. Tighten the air cleaner outlet duct clamp at the MAF/IAT sensor.
16. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
17. Inspect the cooling system for leaks.

Scheme 132

Scheme 133

Scheme 134

Scheme 135

Scheme 136

Scheme 137

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Loosen the air cleaner outlet duct clamps at the following locations: Throttle body Mass airflow/intake air temperature (MAF/IAT) sensor
3. Remove the radiator inlet hose clip from the outlet duct.
4. Remove the air cleaner outlet duct.
5. If necessary, remove the engine sight shield.
6. Remove the radiator vent inlet hose from the radiator hose clips.
7. Reposition the inlet hose clamp at the water pump.
8. Remove the inlet hose from the water pump.
9. Remove the fan blade. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
10. Remove the accessory drive belt.
11. Reposition the outlet hose clamp at the water pump.
12. Remove the outlet hose from the water pump.
13. Reposition the surge tank outlet hose clamp at the water pump.
14. Remove the surge tank outlet hose from the water pump.
15. Reposition the heater inlet hose clamp at the water pump.
16. Remove the heater inlet hose from the water pump.
17. Remove the water pump bolts.
18. Remove the water pump and gaskets.
19. Discard the water pump gaskets.

Important: All gaskets surfaces are to be free of oil or other foreign material during assembly.

1. Install the water pump and NEW gaskets.
2. Install the water pump bolts. 2.1. Tighten the water pump bolts a first pass to 15 N.m (11 lb ft). 2.2. Tighten the water pump bolts a final pass to 30 N.m (22 lb ft).
3. Install the heater inlet hose to the water pump.
4. Position the heater inlet hose clamp at the water pump.
5. Install the surge tank outlet hose to the water pump.
6. Position the surge tank outlet hose clamp at the water pump.
7. Install the outlet hose to the water pump.
8. Position the outlet hose clamp at the water pump.
9. Install the accessory drive belt.
10. Install the fan blade. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
11. Install the inlet hose to the water pump.
12. Position the inlet hose clamp at the water pump.
13. Install the engine vent inlet hose to the radiator hose clips.
14. If necessary, install the engine sight shield. Important: Align the arrow at the throttle body end of the duct with the throttle body attaching stud.
15. Install the air cleaner outlet duct.
16. Install the radiator inlet hose clip to the outlet duct.
17. Tighten the air cleaner outlet duct clamps at the following locations: Throttle body MAF/IAT sensor Tighten the air cleaner outlet duct clamp screws to 7 N.m (62 lb in).
18. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 138

1. Remove the left front fender wheelhouse inner panel (1).
2. Drain the engine coolant and the engine block. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
3. Remove the thermostat housing crossover. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(ref-176275-S23281057122005050500000) .
4. Remove the fan clutch. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
5. Remove the crankshaft balancer.
6. Remove the water pump outlet pipe to water pump nuts.
7. Remove the engine wiring harness retainer from the inner stud.
8. Remove the water pump bolts. Note the location of the bolts. The bolts are three different lengths.
9. Remove the water pump assembly.
10. Remove the water pump outlet pipe gasket.

1. Lubricate the water pump O-ring with engine oil.
2. Install the water pump.
3. Install the water pump bolts. Ensure the correct length bolt is used in the proper location. Tighten the water pump bolts to 21 N.m (15 lb ft).
4. Install the water pump to water pump outlet pipe gasket.
5. Install the engine wiring harness retainer on the water pump outlet pipe inner stud.
6. Install the water pump to water pump outlet pipe nuts. Tighten the water pump to water pump outlet pipe nuts to 21 N.m (1 lb ft).
7. Install the thermostat housing crossover. Refer to «Thermostat Housing Crossover Replacement (6.6L Engine)»(ref-176275-S23281057122005050500000) .
8. Install the crankshaft balancer.
9. Install the fan clutch. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
10. Fill the engine with coolant. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
11. Install the left front fender wheelhouse inner panel (1).

Scheme 139

Scheme 140

Scheme 141

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Remove the drive belt.
3. Remove the fan clutch. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
4. Reposition the outlet hose clamp at the water pump.
5. Remove the outlet hose from the water pump.
6. Reposition the bypass hose clamps at the water pump and water crossover.
7. Remove the bypass hose.
8. Remove the water pump bolts.
9. Remove the water pump.
10. Remove and discard the water pump gaskets.

1. Place NEW water pump gaskets into place.
2. Install the water pump.
3. Install the water pump bolts. Tighten the water pump bolts to 50 N.m (37 lb ft).
4. Install the bypass hose.
5. Position the bypass hose clamps at the water pump and water crossover.
6. Install the outlet hose to the water pump.
7. Position the outlet hose clamp at the water pump.
8. Install the fan clutch. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
9. Install the drive belt.
10. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

1. Remove the left front fender wheelhouse inner panel (1).
2. Remove the water pump. Refer to «Water Pump Replacement (6.6L Engine)»(ref-176275-S37414164702005050500000) .
3. Remove the water pump outlet pipe from the engine oil cooler assembly.
4. Remove and discard the O-ring seal.
5. Remove the gasket and clean the sealing surface.

1. Install a new O-ring seal on the water pump outlet pipe.
2. Lightly lubricate the O-ring seal with engine oil.
3. Install the water pump outlet pipe in the engine oil cooler assembly.
4. Install a new water pump outlet pipe to water pump gasket.
5. Install the water pump.
6. Install the left front fender wheelhouse inner panel (1).

Scheme 142

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Remove the radiator drain cock.

1. Install the radiator drain cock.
2. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 143

Scheme 144

Scheme 145

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

1. Install the upper fan shroud.
2. Install the fan shroud bolts. Tighten the bolts to 9 N.m (80 lb in).
3. Install the fan shroud retainers.
4. Install the inlet radiator hose retainer to the fan shroud
5. Install the throttle body heater hose retainer to the fan shroud.
6. Install the air cleaner outlet duct.
7. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten the clamp screw to 7 N.m (62 lb in).
8. Tighten the air cleaner outlet duct clamp at the mass airflow sensor. Tighten the clamp screw to 7 N.m (62 lb in).

Scheme 146

Scheme 147

Scheme 148

Scheme 149

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

1. Install the upper fan shroud.
2. Install the fan shroud bolts. Tighten the bolts to 9 N.m (80 lb in).
3. Install the fan shroud retainers.
4. Connect the TCM electrical connectors (1).
5. Install the TCM and cover.
6. Tighten the TCM electrical connector bolts. Tighten the bolts to 8 N.m (71 lb in).
7. Install the TCM cover to the fan shroud.
8. Install the TCM cover bolts. Tighten the to 9 N.m (80 lb in).
9. Install the engine harness clip to the PCM cover.
10. Install the A/C line retainer to the fan shroud.
11. Install the air cleaner outlet duct.
12. Tighten the air cleaner outlet duct clamp at the throttle body. Tighten the clamp screws to 7 N.m (62 lb in).
13. Tighten the air cleaner outlet duct clamp at the mass airflow sensor. Tighten the clamp screws to 7 N.m (62 lb in).

1. Remove the cooling fan. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .
2. If equipped with engine oil cooler, remove the oil cooler hose clip from the lower fan shroud.
3. Lift the lower fan shroud up in order to disengage the fan shroud from the retaining clips on the radiator.

1. Install the lower fan shroud to the retaining clips on the radiator and firmly push down.
2. If equipped with the engine oil cooler, Install the oil cooler hose clip to the lower fan shroud.
3. Install the cooling fan. Refer to «Fan Replacement»(ref-176275-S09518946662005050500000) .

Scheme 150

Scheme 151

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000)
2. Reposition the inlet hose clamp from the radiator.
3. Remove the inlet hose from the radiator.
4. Reposition the outlet hose clamp from the radiator.
5. Remove the radiator outlet hose from the radiator.
6. Remove the lower fan shroud. Refer to «Fan Shroud Replacement - Lower»(ref-176275-S30244706742005050500000) .
7. Reposition the radiator vent inlet hose clamp from the radiator.
8. Remove the vent inlet hose from the radiator.
9. Remove the engine oil cooler lines from the radiator.
10. Remove the transmission oil cooler lines from the radiator.
11. Remove the radiator bolts.
12. Remove the radiator from the vehicle.

1. Install the radiator to the vehicle.
2. Install the radiator bolts. Tighten the bolts to 25 N.m (18 lb ft).
3. Install the engine oil cooler lines to the radiator. Refer to «Engine Oil Cooler Hose/Pipe Replacement (6.0L & 8.1L Engines)»(ref-176275-S23676708492005050500000) .
4. Install the transmission oil cooler lines to the radiator.
5. Install the radiator vent inlet hose to the radiator.
6. Reposition the radiator vent inlet hose clamp to the radiator.
7. Install the lower fan shroud. Refer to «Fan Shroud Replacement - Lower»(ref-176275-S30244706742005050500000) .
8. Install the outlet hose to the radiator.
9. Reposition the outlet hose clamp to the radiator.
10. Install the inlet hose to the radiator.
11. Reposition the inlet hose clamp to the radiator.
12. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000)

Scheme 152

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

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

Scheme 153

1. Remove the radiator. Refer to «Radiator Replacement»(ref-176275-S05176518402005050500000) .
2. Remove the radiator air baffle retainers.
3. Remove the radiator air baffles.

1. Install the radiator air baffles.
2. Install the radiator air baffle retainers.
3. Install the radiator. Refer to «Radiator Replacement»(ref-176275-S05176518402005050500000) .

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Disconnect the heater cord from the coolant heater (4).
3. Loosen the bolt retaining the coolant heater to the block.
4. Remove the coolant heater from the engine block.
5. Do not score the machined surface of the hole.
6. Grasp the plug with pliers.
7. Pull the plug from the engine block.
8. Clean the core plug hole in order to remove the following substances: Burrs Compound Paint Rough spots

Scheme 154

1. Coat the O-ring seal and the cleaned surface of the plug opening with water resistant high-temperature grease GM P/N United States 1052196, GM P/N Canada 5264008, or the equivalent. Important: Avoid element contact with the inside walls of the engine block.
2. Tightly push the coolant heater (1) into the engine block.
3. Tighten the bolt on the engine coolant heater until both of the locking wings draw tightly against the inner wall of the engine block. Tighten the bolt in order to retain the engine coolant heater to the engine block to 2 N.m (18 lb in). NOTE: The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.
4. Connect the heater cord to the coolant heater (4).
5. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
6. Inspect the cooling system for leaks.

Scheme 155

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Raise and suitably support the vehicle.
3. Disconnect the coolant heater electrical connector (2). Important: Do not score the surface of the engine block hole when removing the coolant heater.
4. Remove the coolant heater from the engine block.
5. Remove any burrs, sealer, paint or other rough spots.

1. If re-using the old coolant heater, apply thread sealant GM P/N United States 12346004, GM P/N Canada 10953480, or equivalent to the threads.
2. Install the coolant heater to the engine block. Tighten the coolant heater to 50 N.m (37 lb ft). NOTE: The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.
3. Connect the coolant heater electrical connector (2).
4. Lower the vehicle.
5. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 156

1. Drain the cooling system and the engine block. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Raise the vehicle.
3. Remove the right front tire and wheel.
4. Remove the right front fender wheelhouse inner fender (1).
5. Remove the right engine mount.
6. Disconnect the engine coolant heater cord.
7. Loosen the bolt retaining the engine coolant heater to the block.
8. Remove the engine coolant heater from the engine block.
9. Do not score the machined surface of the hole.
10. Grasp the plug with pliers.
11. Pull the plug from the engine block.
12. Clean the core plug hole in order to remove the following substances: Burrs Compound Paint Rough spots

1. Coat the O-ring seal and the cleaned surface of the plug opening with water resistant high-temperature grease GM P/N United States 1052196, GM P/N Canada 5264008, or the equivalent. Important: Avoid element contact with the inside walls of the engine block.
2. Align the coolant heater element to point towards the top of the engine.
3. Tightly push the coolant heater into the engine block.
4. Tighten the bolt on the engine coolant heater until both of the locking wings draw tightly against the inner wall of the engine block. Tighten the bolt in order to retain the engine coolant heater to the engine block to 2 N.m (18 lb in). NOTE: The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.
5. Connect the heater cord to the coolant heater.
6. Install the right engine mount.
7. Install the right front fender wheelhouse inner fender (1).
8. Install the right front tire and wheel.
9. Lower the vehicle.
10. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
11. Inspect for coolant leaks.

Scheme 157

Scheme 158

1. Drain the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .
2. Disconnect the block heater cord from the block heater.
3. Remove the engine block heater.

1. Apply sealant GM P/N 12346004, Canadian P/N 10953480 or equivalent to the threads of the engine block heater.
2. Install the engine block heater into the block. Tighten the engine block heater to 60 N.m (40 lb ft). NOTE: The heater cord must not touch the engine, hot pipes, manifold, or any moving parts. Route the cord to the left front of the engine compartment securing with tie straps as necessary to prevent damage.
3. Connect the block heater cord to the block heater.
4. Fill the cooling system. Refer to «Draining & Filling Cooling System»(ref-176275-S33324703732005050500000) .

Scheme 159

1. Raise and suitably support the vehicle.
2. Disconnect the coolant heater electrical connector (2).
3. Remove the coolant heater cord retainer and bolts.
4. Remove the coolant heater cord.

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

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