Engine Cooling System: Removal & Installation Chevrolet Silverado 2500 HD

Removal Procedure

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
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 at the surge tank.
5. Remove the surge tank inlet hose (1) from the surge tank.

Installation Procedure

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 «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

Scheme 6

Radiator Inlet Hose Replacement

Scheme 7

Radiator Outlet Hose Replacement

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

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

Scheme 8

Radiator Vent Inlet Hose Replacement

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

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

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

1. Disconnect the engine oil cooler quick connect fittings. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(ref-277993-S22255875342008012100000) .
2. If equipped with regular production option (RPO) L76 (6.0L) engine, perform the following. Open the oil cooler hose clip located on the lower fan shroud. Remove the oil cooler hoses from the clip.
3. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
4. If equipped with RPO LY6 (6.0L) engine, remove the oil cooler hoses from the clip.
5. Place a jack or utility stands at the rear of the vehicle.
6. If equipped, remove the engine protection shield. Refer to «Engine Shield Replacement»(ref-278008-S07677231932008012100000) .
7. For both 1500 and 2500 series, support the front differential carrier with a suitable adjustable jack.
8. For 1500 series vehicles, remove the differential carrier right side nuts.
9. Remove the differential carrier left side bolts.
10. Lower the differential carrier.
11. For 2500 series vehicles, remove the differential carrier right side nuts.
12. Remove the differential carrier upper mounting bolt and nut.
13. Remove the differential carrier lower mounting bolt and nut.
14. If equipped with RPO L76 (6.0L) engine, perform the following: Lower the differential carrier. Remove the oil cooler hose adapter bolts (2). Remove the oil cooler hose assembly and gasket. Discard the gasket. Inspect the fittings, connectors, and cooler hoses for damage or distortion.
15. If equipped with RPO LY6 (6.0L) engine, perform the following: Remove the oil cooler hose bracket bolt. (1) Remove the oil cooler hose adapter bolts. (2) Remove the oil cooler hose assembly. Discard the gasket. Inspect the fittings, connectors, and cooler hoses for damage or distortion.

1. If equipped with RPO LY6 (6.0L) engine, perform the following: Install the oil cooler hose assembly and a NEW gasket. Install the oil cooler hose adapter bolts (2). Tighten: Tighten the bolts to 12 N.m (106 lb in). Install the oil cooler hose bracket bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
2. If equipped with a RPO L76 (6.0L) engine, perform the following. Install the oil cooler hose assembly and a NEW gasket. Install the oil cooler hose adapter bolts (2). Tighten: Tighten the bolts to 12 N.m (106 lb in). Install the oil cooler hose bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
3. For 2500 series vehicles, raise the differential carrier into position.
4. Install the differential carrier left side upper bolt and nut until snug.
5. Install the differential carrier left side lower bolt and nut until snug.
6. Install the differential carrier right side nuts. Tighten: Tighten the bolt to 100 N.m (74 lb ft).
7. For 1500 series vehicles, raise the differential carrier into position.
8. Install the differential carrier right side nuts.
9. Install the differential carrier left side bolts. Tighten: Tighten the bolts/nuts to 100 N.m (74 lb ft).
10. If equipped, install the engine protection shield. Refer to «Engine Shield Replacement»(ref-278008-S07677231932008012100000) .
11. Remove the jack or utility stand from the rear of the vehicle.
12. Lower the vehicle.
13. If equipped with RPO LY6 (6.0L) engine, install the oil cooler hoses to the clip.
14. If equipped with RPO L76 (6.0L) engine, perform the following: Install the oil cooler hoses to the hose clip on the fan shroud. Snap the oil cooler hose clip shut.
15. Install the oil cooler lines to the radiator. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(ref-277993-S22255875342008012100000) .

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(ref-277993-S14737020862008012100000) .
2. Remove the 3 engine cooling fan shroud bolts (1).
3. Position the engine cooling fan shroud (1) forward to the radiator.
4. Install a long pin bar into the fan hub (1).
5. Use a J 41240-5A to remove the fan hub nut (2) from the hub in a counterclockwise rotation. See «Special Tools»(ref-277993-S07049521082008012100000) .
6. Remove the fan and the engine cooling fan shroud as an assembly.
7. Remove the fan clutch bolts from the rear of the fan blade.
8. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan and engine cooling fan shroud assembly to the fan hub.
4. Use a J 41240-5A on the fan clutch hub nut (2) to install a long pry bar to the fan clutch hub (1). See «Special Tools»(ref-277993-S07049521082008012100000) . Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Position the engine cooling fan shroud on the 3 mounting brackets (1).
6. Install the bolts. Loosely tighten the top mounting bolt at the oil filler neck.
7. Center the engine cooling fan shroud to the fan blade in 3 places (1).
8. Fully tighten the 3 engine cooling fan shroud bolts (1). Tighten: Tighten the bolts to 8 N.m (71 lb in).
9. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(ref-277993-S14737020862008012100000) .

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(ref-277993-S02298769122008012100000) .
2. Install the J 46406 to the fan clutch. See «Special Tools»(ref-277993-S07049521082008012100000) .
3. Remove the fan hub nut from the water pump in a counterclockwise rotation.
4. Remove the fan clutch bolts from the rear of the fan blade.
5. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan assembly.
4. Install the J 46406 to the fan clutch. See «Special Tools»(ref-277993-S07049521082008012100000) . Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(ref-277993-S02298769122008012100000) .

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(ref-277993-S14737020862008012100000) .
2. Remove the 3 engine cooling fan shroud bolts (1).
3. Position the engine cooling fan shroud (1) forward to the radiator.
4. Install a long pin bar into the fan hub (1).
5. Use a J 41240-5A to remove the fan hub nut (2) from the hub in a counterclockwise rotation. See «Special Tools»(ref-277993-S07049521082008012100000) .
6. Remove the fan and the engine cooling fan shroud as an assembly.
7. Remove the fan clutch bolts from the rear of the fan blade.
8. Separate the fan clutch from the fan blade.

1. Install the fan clutch onto the fan blade.
2. Install the fan clutch bolts. Tighten: Tighten the bolts to 23 N.m (17 lb ft).
3. Install the fan and engine cooling fan shroud assembly to the fan hub.
4. Use a J 41240-5A on the fan clutch hub nut (2) to install a long pry bar to the fan clutch hub (1). See «Special Tools»(ref-277993-S07049521082008012100000) . Tighten: Tighten the nut clockwise to 56 N.m (41 lb ft).
5. Position the engine cooling fan shroud on the 3 mounting brackets (1).
6. Install the bolts. Loosely tighten the top mounting bolt at the oil filler neck.
7. Center the engine cooling fan shroud to the fan blade in 3 places (1).
8. Fully tighten the 3 engine cooling fan shroud bolts (1). Tighten: Tighten the bolts to 8 N.m (71 lb in).
9. Install «Engine Coolant Fan Upper Shroud Replacement (Mechanical)»(ref-277993-S02298769122008012100000) or «Engine Coolant Fan Upper Shroud Replacement (Automatic Transmission - Diesel)»(ref-277993-S14737020862008012100000) .

Scheme 9

1. Remove the drive belt. Refer to «DRIVE BELT REPLACEMENT»(ref-278093-S32518826922008012100000)
2. Remove the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(ref-277993-S05265579852008012100000)
3. Disconnect the camshaft position (CMP) sensor electrical connector.
4. Remove the fan pulley bolts/nuts.
5. Remove the fan pulley.

Scheme 10

1. Install the fan pulley.
2. Install the fan pulley bolts/nuts. Tighten the bolts/nuts to 41 N.m (30 lb ft).
3. Connect the CMP sensor electrical connector
4. Install the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(ref-277993-S05265579852008012100000)
5. Install the drive belt. Refer to «DRIVE BELT REPLACEMENT»(ref-278093-S32518826922008012100000)

1. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-278093-S32518826922008012100000) .
2. Remove the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(ref-277993-S05265579852008012100000) .
3. Disconnect the camshaft position (CMP) sensor electrical connector.
4. Remove the fan pulley bolts/nuts.
5. Remove the fan pulley.

1. Install the fan pulley.
2. Install the fan pulley bolts/nuts. Tighten: Tighten the bolts/nuts to 41 N.m (30 lb ft).
3. Connect the CMP sensor electrical connector.
4. Install the fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(ref-277993-S05265579852008012100000) .
5. Install the drive belt. Refer to «Drive Belt Replacement»(ref-278093-S32518826922008012100000) .

1. Remove the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(ref-277993-S33602824782008012100000) .
2. Remove the cooling fan blade retainers.
3. Remove the cooling fan blades.

1. Install the cooling fan blades.
2. Install the cooling fan blade retainers.
3. Install the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(ref-277993-S33602824782008012100000) .

1. Remove the cooling blade(s). Refer to «Engine Cooling Fan Replacement»(ref-277993-S22755946642008012100000) .
2. Remove the cooling fan motor bolts.
3. Remove the cooling fan motor(s).

1. Install the cooling fan motor(s).
2. Install the cooling fan motor bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
3. Install the cooling fan blades. Refer to «Engine Cooling Fan Replacement»(ref-277993-S22755946642008012100000) .

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

1. Install the cooling fan and shroud.
2. Install the cooling fan shroud bolts. Tighten: Tighten the bolts to 9 N.m (80 lb in).
3. If equipped, install the cooler lines to the clip and close the clip.
4. Connect the electrical connectors to the cooling fans.
5. Install the clip attaching the wiring harness to the shroud.
6. Install the transmission cooling line bolts to fan shroud. Tighten: Tighten the bolts to 4 N.m (35 lb in).
7. If necessary, install the surge tank inlet hose to the radiator.
8. If necessary, reposition the surge tank inlet hose clamp at the radiator.
9. Engage the radiator inlet hose clip (2) at the fan shroud.

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(ref-278093-S40044916342008012100000) .
2. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
3. Reposition the coolant inlet hose clamp.
4. Disconnect the turbocharger coolant inlet hose from the turbocharger bypass valve.
5. Remove the turbocharger bypass valve and washer.

1. Install the turbocharger bypass valve and washer. Tighten: Tighten the valve to 60 N.m (44 lb ft).
2. Connect the turbocharger coolant inlet hose to the turbocharger bypass valve.
3. Position the coolant inlet hose clamp.
4. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
5. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(ref-278093-S40044916342008012100000) .

1. Remove the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(ref-278093-S40044916342008012100000) .
2. Remove the air cleaner. Refer to «Air Cleaner Assembly Replacement»(ref-278042-S29586781132008012100000) .
3. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
4. Remove the charged air cooler outlet pipe from the turbocharger and the charged air cooler. Refer to «Charge Air Cooler Outlet Pipe Replacement»(ref-278042-S22110933232008012100000) .
5. Reposition the turbocharger coolant inlet hose clamp at the bypass valve.
6. Remove the turbocharger coolant inlet hose banjo bolt (1).
7. Remove the inlet hose washer and inlet line.

1. Install the inlet hose washer and inlet line.
2. Install the turbocharger coolant inlet hose banjo bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
3. Position the turbocharger coolant inlet hose clamp at the bypass valve.
4. Remove the tape from the turbocharger openings.
5. Install the charged air cooler outlet pipe to the turbocharger and the charged air cooler. Refer to «Charge Air Cooler Outlet Pipe Replacement»(ref-278042-S22110933232008012100000) .
6. Install the air cleaner. Refer to «Air Cleaner Assembly Replacement»(ref-278042-S29586781132008012100000) .
7. Install the intake manifold cover. Refer to «Intake Manifold Cover Replacement»(ref-278093-S40044916342008012100000) .
8. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

1. Remove the turbocharger coolant inlet pipe. Refer to «Turbocharger Coolant Hoses/Pipes Replacement (LMM - Inlet Pipe)»(ref-277993-S31213227442008012100000) .
2. Remove the generator mounting bracket. Refer to «Generator Bracket Replacement (6.6L)»(ref-278006-S23149380482008012100000) .
3. Remove the exhaust gas recirculation (EGR) cooler assembly. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(ref-278042-S32899914432008012100000) .
4. Remove the cooling fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(ref-277993-S05265579852008012100000) .
5. Reposition the hose clamp at the bypass pipe.
6. Remove the turbocharger coolant outlet hose from the bypass pipe.
7. Reposition the turbocharger coolant outlet hose clamp.
8. Remove the turbocharger coolant outlet hose from the pipe on the turbocharger.
9. Remove the turbocharger coolant outlet pipe bolt and nut.
10. If necessary, remove the turbocharger. Refer to «Turbocharger Replacement»(ref-278093-S28115899052008012100000) .
11. If necessary, remove the coolant outlet pipe clip bolt (3) from the turbocharger.
12. If necessary, remove the coolant outlet pipe.

1. If necessary, install the coolant outlet pipe.
2. If necessary, install the coolant outlet pipe clip bolt (3) to the turbocharger. Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. If necessary, install the turbocharger. Refer to «Turbocharger Replacement»(ref-278093-S28115899052008012100000) .
4. Install the turbocharger coolant outlet pipe bolt and nut. Tighten: Tighten the bolt/nut to 9 N.m (80 lb in).
5. Install the turbocharger coolant outlet hose to the pipe on the turbocharger.
6. Position the turbocharger coolant outlet hose clamp.
7. Install the turbocharger coolant outlet hose to the bypass pipe.
8. Position the hose clamp at the bypass pipe.
9. Install the cooling fan clutch. Refer to «Fan Clutch Replacement (Diesel)»(ref-277993-S05265579852008012100000) .
10. Install the EGR cooler assembly. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(ref-278042-S32899914432008012100000) .
11. Install the generator mounting bracket. Refer to «Generator Bracket Replacement (6.6L)»(ref-278006-S23149380482008012100000) .
12. Install the turbocharger coolant inlet pipe. Refer to «Turbocharger Coolant Hoses/Pipes Replacement (LMM - Inlet Pipe)»(ref-277993-S31213227442008012100000) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Reposition the EGR cooler pipe clamp (1) and remove the EGR cooler pipe hose from the EGR cooler tube.
3. Remove the upper EGR cooler pipe nut (1).
4. Remove the lower EGR cooler pipe bolt (1).
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
6. Remove the EGR cooler pipe bolt (1) and bracket (2).
7. Remove the EGR cooler pipe from the engine.

1. Position the EGR cooler pipe to the engine.
2. Install the EGR cooler pipe bracket (2) and bolt (1). Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. Lower the vehicle.
4. Install the lower EGR cooler pipe bolt (1).
5. Install the upper EGR cooler pipe nut (1). Tighten: Tighten the bolt to 9 N.m (80 lb in).
6. Install the EGR cooler pipe hose to the EGR cooler tube and reposition the EGR cooler pipe clamp (1).
7. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Reposition the EGR cooler pipe clamp (1) and remove the EGR cooler pipe hose from the EGR cooler tube.
3. Remove the upper EGR cooler pipe nut (1).
4. Remove the lower EGR cooler pipe bolt (1).
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
6. Remove the EGR cooler pipe bolt (1) and bracket (2).
7. Remove the EGR cooler pipe from the engine.

1. Position the EGR cooler pipe to the engine.
2. Install the EGR cooler pipe bracket (2) and bolt (1). Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. Lower the vehicle.
4. Install the lower EGR cooler pipe bolt (1).
5. Install the upper EGR cooler pipe nut (1). Tighten: Tighten the bolt to 9 N.m (80 lb in).
6. Install the EGR cooler pipe hose to the EGR cooler tube and reposition the EGR cooler pipe clamp (1).
7. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

1. Remove the radiator inlet hose. Refer to «Radiator Inlet Hose Replacement»(ref-277993-S10996125322008012100000) .
2. Remove the turbocharger coolant bypass valve. Refer to «Turbocharger Coolant Bypass Valve Replacement»(ref-277993-S23087384722008012100000) .
3. Remove the bolts and wiring harness bracket at the thermostat housing.
4. Position the bracket and wiring harness aside.
5. Disconnect the main engine electrical harness connectors. Lift up on the latches (1) in order to disconnect the connectors.
6. Open the harness clip (2).
7. Remove the main engine electrical harness connectors.
8. Disconnect the turbocharger vane position sensor electrical connector (1).
9. Unclip the main engine electrical harness connectors from the main electrical connector harness bracket.
10. Remove the main electrical connector harness bracket bolts (1).
11. Remove the main electrical connector harness bracket (2) and position aside.
12. Remove the manifold intake temperature sensor electrical connector from the water tube bracket.
13. Remove the water outlet bolts.
14. Remove the water outlet.
15. Remove and discard the O-ring seal.

1. Install a NEW O-ring seal to the water outlet.
2. Lubricate the O-ring seal with clean engine coolant.
3. Install the water outlet.
4. Install the water outlet bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
5. Install the manifold intake temperature sensor electrical connector to the water tube bracket.
6. Install the main electrical harness bracket.
7. Install the main electrical harness bracket bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
8. Install the main engine electrical harness connector bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
9. Install the main electrical connector harness bracket (2).
10. Install the main electrical connector harness bracket bolts (1). Tighten: Tighten the bolts to 21 N.m (15 lb ft).
11. Clip the main engine electrical harness connectors to the main electrical connector harness bracket.
12. Connect the turbocharger vane position sensor electrical connector (1).
13. Connect the main engine electrical harness connectors.
14. Push down on the latches (1) in order to connect the connectors.
15. Close the harness clip (2).
16. Install the wiring harness bracket and bolts to the thermostat housing. Tighten: Tighten the bolts to 10 N.m (89 lb in).
17. Install the turbocharger coolant bypass valve. Refer to «Turbocharger Coolant Bypass Valve Replacement»(ref-277993-S23087384722008012100000) .
18. Install the radiator inlet hose. Refer to «Radiator Inlet Hose Replacement»(ref-277993-S10996125322008012100000) .

1. Remove the air cleaner outlet resonator duct. Refer to «Air Cleaner Outlet Resonator Replacement»(ref-278028-S22321652382008012100000) .
2. Remove the radiator inlet hose. Refer to «Radiator Inlet Hose Replacement»(ref-277993-S10996125322008012100000) .
3. Remove the turbocharger coolant bypass valve. Refer to «Turbocharger Coolant Bypass Valve Replacement»(ref-277993-S23087384722008012100000) .
4. Remove the water outlet bolts.
5. Remove the water outlet.
6. Remove and discard the gasket.

1. Install a NEW gasket to the water outlet.
2. Lubricate the O-ring seal with clean engine coolant.
3. Install the water outlet.
4. Install the water outlet bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
5. Install the radiator inlet hose. Refer to «Radiator Inlet Hose Replacement»(ref-277993-S10996125322008012100000) .
6. Install the air cleaner outlet resonator duct. Refer to «Air Cleaner Outlet Resonator Replacement»(ref-278028-S22321652382008012100000) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
3. Reposition the radiator outlet hose clamp at the water pump inlet.
4. Remove the radiator outlet hose from the water pump inlet.
5. Remove the water pump inlet bolts.
6. Remove the water pump inlet from the water pump.
7. Remove and discard the water pump inlet seal.

1. Install a NEW water pump inlet seal to the water pump inlet.
2. Position the water pump inlet to the water pump.
3. Install the water pump inlet bolts. Tighten: Tighten the bolts to 15 N.m (11 lb ft).
4. Install the radiator outlet hose to the water pump inlet.
5. Position the radiator outlet hose clamp at the water pump inlet.
6. Install the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
7. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

1. Remove the thermostat housing. Refer to «Engine Coolant Thermostat Housing Replacement (LY2, LH6, LY5, LMG, LY6)»(ref-277993-S39678942242008012100000) .
2. Remove the thermostat.

1. Install the thermostat.
2. Install the thermostat housing. Refer to «Engine Coolant Thermostat Housing Replacement (LY2, LH6, LY5, LMG, LY6)»(ref-277993-S39678942242008012100000) .

1. Remove the water outlet tube. Refer to «Water Outlet Tube Replacement (LU3)»(ref-277993-S01592047882008012100000) .
2. Remove the water outlet.
3. Remove the thermostat.
4. Clean the sealing surface of the water outlet.
5. Clean the sealing surface of the intake manifold.
6. 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 tube. Refer to «Water Outlet Tube Replacement (LU3)»(ref-277993-S01592047882008012100000) .

1. Remove the water outlet. Refer to «Water Outlet Tube Replacement (LMM)»(ref-277993-S06178821122008012100000) .
2. Remove the bolt for the fuel line bracket.
3. Remove the fuel line bracket.
4. Remove the thermostat housing cover bolts (1).
5. Remove the thermostat housing cover.
6. Remove the thermostats and seals.

1. Install the thermostats and seals to the thermostat housing. The rear thermostat (4) has 2 vent valves. Install with the vent valves towards the rear of engine.
2. Install the thermostat housing cover.
3. Install the thermostat housing cover bolts (1). Tighten: Tighten the bolts to 21 N.m (15 lb ft).
4. Install the fuel line bracket.
5. Install the fuel line bracket bolt. Tighten: Tighten the bolt to 21 N.m (15 lb ft).
6. Install the water outlet tube. Refer to «Water Outlet Tube Replacement (LMM)»(ref-277993-S06178821122008012100000) .

Scheme 11

1. Drain the cooling system. Refer to «Cooling System Draining and Filling»(ref-277993-S13763505242012122600000)
2. Remove the fan pulley. Refer to «Fan Pulley Replacement»(ref-277993-S25924054562012122600000)
3. Remove Thermostat Bypass Pipe Bolts. 21 N.m (16 lb ft)
4. Thermostat Bypass Pipe to Turbocharger Outlet Cooler Pipe Clamp. Procedure Reposition the thermostat bypass pipe to turbocharger outlet cooler pipe clamp using the BO-38185 Hose Clamp Pliers. Replace hose clamp if necessary.
5. Thermostat Bypass Pipe Tip: Install new O-ring seals. Lubricate using clean engine coolant.

1. Remove the air cleaner. Refer to «Air Cleaner Assembly Replacement»(ref-278042-S29586781132008012100000) .
2. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
3. Disconnect the negative battery cables. Refer to «Battery Negative Cable Disconnection and Connection (w/Single Battery)»(ref-278006-S00548352152008012100000) or «Battery Negative Cable Disconnection and Connection (w/Auxiliary Battery)»(ref-278006-S06440924722008012100000) or «Battery Negative Cable Disconnection and Connection (w/Dual Batteries)»(ref-278006-S13593468912008012100000) .
4. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-278093-S32518826922008012100000) .
5. Disconnect the air conditioning (A/C) pressure switch electrical connector (1).
6. Disconnect the A/C compressor clutch electrical connector (2).
7. Remove the generator bracket. Refer to «Generator Bracket Replacement (6.6L)»(ref-278006-S23149380482008012100000) .
8. Remove the front oil fill tube. Refer to «Oil Filler Tube Replacement»(ref-278093-S35564305712008012100000) .
9. Disconnect the engine coolant temperature (ECT) sensor electrical connectors.
10. Remove the water outlet. Refer to «Water Outlet Tube Replacement (LMM)»(ref-277993-S06178821122008012100000) .
11. Without disconnecting the power steering hoses, remove the power steering pump bolts and the power steering pump. Reposition the power steering pump and secure to the side. Refer to «Power Steering Pump Replacement (6.6L)»(ref-278038-S08932193802008012100000) .
12. Remove the power steering pump bracket. Refer to «Air Conditioning (A/C) Compressor and Power Steering Pump Bracket Replacement»(ref-278093-S11754582902008012100000) .
13. Remove the bolts and wiring harness bracket at the thermostat housing.
14. Position the bracket and wiring harness aside.
15. Remove the cooling fan pulley. Refer to «Cooling Fan Pulley Replacement»(ref-277993-S39336834742008012100000) .
16. Reposition the turbocharger coolant return pipe hose clamp.
17. Remove the turbocharger coolant return pipe hose.
18. Remove the fuel line bracket bolt at the thermostat housing crossover.
19. Remove the water pump inlet pipe bolts.
20. Remove the thermostat housing crossover bolts and nuts.
21. Remove the thermostat housing crossover, with the bypass pipe.
22. Remove and discard the thermostat bypass pipe to water pump O-ring seal.
23. Remove and discard the thermostat housing crossover gaskets.
24. If necessary, perform the following: Remove the thermostat bypass pipe from the thermostat housing crossover. Remove and discard the thermostat bypass pipe O-ring seal. Remove the thermostat cover bolts and cover. Remove the thermostats. Remove and discard the thermostat seals.
25. If required, clean and inspect the thermostat housing. Refer to «Engine Coolant Thermostat Housing Cleaning and Inspection»(ref-278096-S10115630142008012100000) .

1. If necessary, perform the following: Install NEW seals to the thermostats. Install the thermostats. Install the thermostat cover and bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft). Install a NEW O-ring seal to the thermostat bypass pipe. Install the thermostat bypass pipe to the thermostat housing.
2. Install a NEW thermostat bypass pipe to water pump O-ring seal.
3. Install the thermostat housing crossover using NEW gaskets.
4. Install the thermostat housing crossover bolts and nuts. Tighten: Tighten the bolts/nuts to 21 N.m (15 lb ft).
5. Install the water pump inlet pipe bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
6. Install the fuel line bracket bolt at the thermostat housing crossover. Tighten: Tighten the bolt to 21 N.m (15 lb ft).
7. Install the turbocharger coolant return pipe hose.
8. Position the turbocharger coolant return pipe hose clamp.
9. Install the wiring harness bracket and bolts to the thermostat housing. Tighten: Tighten the bolts to 10 N.m (89 lb in).
10. Install the cooling fan pulley. Refer to «Cooling Fan Pulley Replacement»(ref-277993-S39336834742008012100000) .
11. Install the power steering pump bracket. Refer to «Air Conditioning (A/C) Compressor and Power Steering Pump Bracket Replacement»(ref-278093-S11754582902008012100000) .
12. Reposition the power steering pump and install the power steering pump bolts. Refer to «Power Steering Pump Replacement (6.6L)»(ref-278038-S08932193802008012100000) .
13. Install the water outlet. Refer to «Water Outlet Tube Replacement (LMM)»(ref-277993-S06178821122008012100000) .
14. Connect the ECT sensor electrical connectors.
15. Install the front oil fill tube. Refer to «Oil Filler Tube Replacement»(ref-278093-S35564305712008012100000) .
16. Install the generator bracket. Refer to «Generator Bracket Replacement (6.6L)»(ref-278006-S23149380482008012100000) .
17. Connect the A/C compressor clutch electrical connector (2).
18. Connect the A/C cut out switch electrical connector (1).
19. Install the drive belt. Refer to «Drive Belt Replacement»(ref-278093-S32518826922008012100000) .
20. Connect the negative battery cables. Refer to «Battery Negative Cable Disconnection and Connection (w/Single Battery)»(ref-278006-S00548352152008012100000) or «Battery Negative Cable Disconnection and Connection (w/Auxiliary Battery)»(ref-278006-S06440924722008012100000) or «Battery Negative Cable Disconnection and Connection (w/Dual Batteries)»(ref-278006-S13593468912008012100000) .
21. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
22. Install the air cleaner. Refer to «Air Cleaner Assembly Replacement»(ref-278042-S29586781132008012100000) .

1. If replacing the rear coolant air bleed covers, remove the intake manifold. Refer to «Intake Manifold Replacement (L92 - First Design)»(ref-278040-S08636564402008012100000) or «Intake Manifold Replacement (L92 - Second Design)»(ref-278040-S32486521642008012100000) or «Intake Manifold Replacement (LH6, LMG, LY5 and L76)»(ref-278040-S04366265542008012100000) . Otherwise proceed to the next step.
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
3. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
4. Reposition the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
5. Remove the radiator vent inlet hose (2) from the coolant air bleed pipe fitting.
6. Remove the coolant air bleed pipe bolts (309) (intake manifold shown removed for clarity).
7. Remove the coolant air bleed pipe (307) and seals (308).
8. Remove the coolant air bleed cover bolts (312), if required.
9. Remove the coolant air bleed covers (313) and seals (308), if required.
10. Remove the seals (308) from the coolant air bleed pipe and/or covers.
11. Discard the seals.

1. Install the seals onto the coolant air bleed pipe and/or covers.
2. Install the coolant air bleed pipe (307) and seals (308) onto the cylinder heads.
3. Install the coolant air bleed pipe bolts (309). Tighten: Tighten the bolts to 12 N.m (106 lb in).
4. Install the coolant air bleed covers (313) and seals (308), if required.
5. Install the coolant air bleed cover bolts (312), if required. Tighten: Tighten the bolts to 12 N.m (106 lb in).
6. Install the radiator vent inlet hose (2) to the coolant air bleed pipe fitting.
7. Position the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
8. Install the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
9. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
10. If the rear coolant air bleed covers were replaced, install the intake manifold. Refer to «Intake Manifold Replacement (L92 - First Design)»(ref-278040-S08636564402008012100000) or «Intake Manifold Replacement (L92 - Second Design)»(ref-278040-S32486521642008012100000) or «Intake Manifold Replacement (LH6, LMG, LY5 and L76)»(ref-278040-S04366265542008012100000) .

1. If replacing the rear coolant air bleed covers, remove the intake manifold. Refer to «Intake Manifold Replacement (LY2 and LY6)»(ref-278040-S39433866062008012100000) . Otherwise proceed to the next step.
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
3. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
4. Reposition the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
5. Remove the radiator vent inlet hose (2) from the coolant air bleed pipe fitting.
6. Remove the coolant air bleed pipe bolts (309) (intake manifold shown removed for clarity).
7. Remove the coolant air bleed pipe (307) and seals (308).
8. Remove the coolant air bleed cover bolts (312), if required.
9. Remove the coolant air bleed covers (313) and seals (308), if required.
10. Remove the seals (308) from the coolant air bleed pipe and/or covers.
11. Discard the seals.

1. Install the seals onto the coolant air bleed pipe and/or covers.
2. Install the coolant air bleed pipe (307) and seals (308) onto the cylinder heads.
3. Install the coolant air bleed pipe bolts (309). Tighten: Tighten the bolts to 12 N.m (106 lb in).
4. Install the coolant air bleed covers (313) and seals (308), if required.
5. Install the coolant air bleed cover bolts (312), if required. Tighten: Tighten the bolts to 12 N.m (106 lb in).
6. Install the radiator vent inlet hose (2) to the coolant air bleed pipe fitting.
7. Position the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
8. Install the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
9. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
10. If the rear coolant air bleed covers were replaced, install the intake manifold. Refer to «Intake Manifold Replacement (LY2 and LY6)»(ref-278040-S39433866062008012100000) .

1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
2. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
3. Reposition the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
4. Remove the radiator vent inlet hose (2) from the coolant air bleed pipe fitting.
5. Reposition the radiator inlet hose clamp (3) at the water pump.
6. Remove the radiator inlet hose from the water pump.
7. Reposition the radiator inlet hose and vent inlet hose out of the way.
8. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(ref-278040-S10101317902008012100000) .
9. Reposition the radiator outlet hose clamp at the water pump.
10. Remove the radiator outlet hose from the water pump.
11. Reposition the outlet hose out of the way.
12. Reposition the radiator surge tank outlet hose clamp at the water pump (1).
13. Remove the radiator surge tank outlet hose (2) from the water pump.
14. Reposition the outlet hose out of the way.
15. Reposition the heater inlet hose clamp (1) at the water pump.
16. Remove the heater inlet hose (2) from the water pump.
17. Reposition the inlet hose out of the way.
18. Remove the water pump bolts (301).
19. Remove the water pump (300) and gaskets (309). Discard the gaskets.

Note. DO NOT use cooling system seal tabs, or similar compounds, unless otherwise instructed. The use of cooling system seal tabs, or similar compounds, may restrict coolant flow through the passages of the cooling system or the engine components. Restricted coolant flow may cause engine overheating and/or damage to the cooling system or the engine components/assembly.

1. Position the water pump (300) and NEW gaskets (306) to the engine block.
2. Install the water pump bolts (301). Tighten: Tighten the bolts a first pass to 15 N.m (11 lb ft). Tighten the bolts a final pass to 30 N.m (22 lb ft).
3. Position and install the heater inlet hose (2) to the water pump.
4. Position the heater inlet hose clamp (1) at the water pump.
5. Position and install the radiator surge tank outlet hose (2) to the water pump.
6. Position the radiator surge tank outlet hose clamp at the water pump (1).
7. Position and install the radiator outlet hose to the water pump.
8. Position the radiator outlet hose clamp at the water pump.
9. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(ref-278040-S10101317902008012100000) .
10. Position the radiator inlet hose and vent inlet hose to the correct position.
11. Install the radiator inlet hose to the water pump.
12. Position the radiator inlet hose clamp (3) at the water pump.
13. Install the radiator vent inlet hose (2) to the coolant air bleed pipe fitting.
14. Position the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
15. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
16. Install the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .

1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .
2. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
3. Reposition the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
4. Remove the radiator vent inlet hose (2) from the coolant air bleed pipe fitting.
5. Reposition the radiator inlet hose clamp (3) at the water pump.
6. Remove the radiator inlet hose from the water pump.
7. Reposition the radiator inlet hose and vent inlet hose out of the way.
8. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(ref-278040-S10101317902008012100000) .
9. Reposition the radiator outlet hose clamp at the water pump.
10. Remove the radiator outlet hose from the water pump.
11. Reposition the outlet hose out of the way.
12. Reposition the radiator surge tank outlet hose clamp (1) at the water pump.
13. Remove the radiator surge tank outlet hose (2) from the water pump.
14. Reposition the outlet hose out of the way.
15. Reposition the heater inlet hose clamp (1) at the water pump.
16. Remove the heater inlet hose (2) from the water pump.
17. Reposition the inlet hose out of the way.
18. Remove the water pump bolts (301).
19. Remove the water pump (300) and gaskets (309). Discard the gaskets.

Note. DO NOT use cooling system seal tabs, or similar compounds, unless otherwise instructed. The use of cooling system seal tabs, or similar compounds, may restrict coolant flow through the passages of the cooling system or the engine components. Restricted coolant flow may cause engine overheating and/or damage to the cooling system or the engine components/assembly.

1. Position the water pump (300) and NEW gaskets (306) to the engine block.
2. Install the water pump bolts (301). Tighten: Tighten the bolts a first pass to 15 N.m (11 lb ft). Tighten the bolts a final pass to 30 N.m (22 lb ft).
3. Position and install the heater inlet hose (2) to the water pump.
4. Position the heater inlet hose clamp (1) at the water pump.
5. Position and install the radiator surge tank outlet hose (2) to the water pump.
6. Position the radiator surge tank outlet hose clamp (1) at the water pump.
7. Position and install the radiator outlet hose to the water pump.
8. Position the radiator outlet hose clamp at the water pump.
9. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(ref-278040-S10101317902008012100000) .
10. Position the radiator inlet hose and vent inlet hose to the correct position.
11. Install the radiator inlet hose to the water pump.
12. Position the radiator inlet hose clamp (3) at the water pump.
13. Install the radiator vent inlet hose (2) to the coolant air bleed pipe fitting.
14. Position the radiator vent inlet hose clamp (1) at the coolant air bleed pipe fitting.
15. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
16. Install the air cleaner outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(ref-278009-S05538658182008012100000) .

Scheme 12

1. Remove the left wheelhouse inner panel. Refer to «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(ref-278008-S33611937342008012100000) or «Front Wheelhouse Liner Replacement - Left Side (GMC)»(ref-278008-S20399281122008012100000) .
2. Remove the radiator outlet hose. Refer to «Radiator Outlet Hose Replacement»(ref-277993-S38234622352008012100000) .
3. Remove the thermostat bypass pipe. Refer to «Thermostat Bypass Pipe Replacement Diesel»(ref-277993-S16655220382012122600000) .
4. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(ref-278093-S37428833222008012100000) .
5. Remove the water pump to engine coolant pipe nuts (2) from the studs (1).
6. Remove the engine wiring harness retainer from the inner stud.
7. Remove the water pump bolts. Note the location of the bolts. The bolts are three different lengths.
8. Remove the water pump.
9. Remove and discard the water pump O-ring and coolant pipe gasket.
10. If required, clean and inspect the water pump. Refer to «Water Pump Cleaning and Inspection»(ref-278096-S05450329182008012100000) .

Scheme 13

1. Lubricate the water pump O-ring with engine oil.
2. Install the water pump outlet pipe gasket (4) and the lubricated water pump O-ring (3). NOTE: Refer to «Fastener Notice»(ref-277992-S11872939162008012100000) .
3. Install the water pump nut (1) and bolts (2). Ensure the correct length bolt is used in the proper location and tighten to 25 N.m (18 lb ft)
4. Install the engine wiring harness retainer on the water pump outlet pipe inner stud.
5. Install the water pump bolts. Ensure the correct length bolt is used in the proper location.Install the water pump to water pump outlet pipe nuts (2) to the studs (1) and tighten to 25 N.m (18 lb ft).
6. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(ref-278093-S37428833222008012100000) .
7. Install the thermostat bypass pipe. Refer to «Thermostat Bypass Pipe Replacement Diesel»(ref-277993-S16655220382012122600000) .
8. Install the radiator outlet hose. Refer to «Radiator Outlet Hose Replacement»(ref-277993-S38234622352008012100000)
9. Install the left wheelhouse inner panel. Refer to «Front Wheelhouse Liner Replacement - Left Side (Chevrolet)»(ref-278008-S33611937342008012100000) or «Front Wheelhouse Liner Replacement - Left Side (GMC)»(ref-278008-S20399281122008012100000) .

1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Resonator Replacement»(ref-278028-S22321652382008012100000) .
2. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-278083-S23085427542008012100000) .
3. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
4. Reposition the radiator outlet hose clamps at the surge tank and water pump.
5. Remove the radiator outlet hose from the surge tank.
6. Remove the radiator outlet hose from the water pump.
7. Reposition the water pump inlet hose clamps.
8. Remove the water pump inlet hose.
9. Using J 41240 , hold the water pump pulley, remove the water pump pulley bolts.
10. Remove the water pump bolts.
11. Remove the water pump.
12. Remove and discard the water pump gaskets.
13. Clean and inspect the water pump, if necessary. Refer to «Water Pump Cleaning and Inspection»(ref-278083-S04993474172008012100000) .

1. If reusing the old fasteners, apply sealant GM P/N 12346004, (Canadian P/N 10953480), or equivalent to the threads of the water pump bolts.
2. Install NEW water pump gaskets and the water pump. NOTE: Refer to «Fastener Notice»(ref-277992-S11872939162008012100000) .
3. Install the water pump bolts. Tighten: Tighten the bolts to 45 N.m (33 lb ft).
4. Using J 41240 , hold the water pump pulley, install the water pump pulley bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
5. Install the water pump inlet hose.
6. Position the water pump inlet hose clamps.
7. Install the radiator outlet hose to the water pump.
8. Install the radiator outlet hose to the surge tank.
9. Position the radiator outlet hose clamps at the surge tank and water pump.
10. Install the drive belt. Refer to «Drive Belt Replacement»(ref-278083-S23085427542008012100000) .
11. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Resonator Replacement»(ref-278028-S22321652382008012100000) .
12. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
13. Inspect the cooling system for leaks.

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

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

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

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

1. Remove the cooling fan. Refer to «Fan Replacement (Diesel)»(ref-277993-S07886282582008012100000) or «Fan Replacement (Mechanical)»(ref-277993-S18456074292008012100000) .
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 and ensure it is centered over lower radiator support.
2. If equipped with the engine oil cooler, Install the oil cooler hose clip to the lower fan shroud.
3. Install the cooling fan. Refer to «Fan Replacement (Diesel)»(ref-277993-S07886282582008012100000) or «Fan Replacement (Mechanical)»(ref-277993-S18456074292008012100000) .

1. Remove the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(ref-277993-S33602824782008012100000) .
2. Remove the radiator outlet hose for the 4.3L engine, or the 4.8L, 5.3L and 6.0L engines. Refer to «Radiator Outlet Hose Replacement»(ref-277993-S38234622352008012100000) .
3. Disconnect the engine oil cooler lines from the radiator, if necessary. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(ref-277993-S22255875342008012100000) .
4. Disconnect the transmission oil cooler lines from the radiator, if necessary. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(ref-278052-S31030305662008012100000) .
5. Remove the radiator bolts.
6. Remove the radiator.

1. Install the radiator.
2. Install the radiator bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
3. Connect the transmission oil cooler lines to the radiator, if necessary. Refer to «Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection»(ref-278052-S31030305662008012100000) .
4. Connect the engine oil cooler lines to the radiator, if necessary. Refer to «Engine Oil Cooler Pipe/Hose Quick Connect Fitting»(ref-277993-S22255875342008012100000) .
5. Install the radiator outlet hose for the 4.3L engine, or the 4.8L, 5.3L and 6.0L engines. Refer to «Radiator Outlet Hose Replacement»(ref-277993-S38234622352008012100000) .
6. Install the cooling fan and shroud. Refer to «Cooling Fan and Shroud Replacement»(ref-277993-S33602824782008012100000) .

Scheme 14

Radiator Replacement (LLM)

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

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

1. Drain the cooling system/engine block. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
3. Remove the oil pan skid plate bolts and plate, if equipped.
4. For vehicles with regular production option (RPO) L76 (6.0L), perform the following steps. Otherwise, proceed to step 9.
5. Remove the oil cooler hose bracket bolt (1), if equipped.
6. Remove the oil cooler hose adapter bolts (2), if equipped.
7. Remove and discard the oil cooler hose adapter gasket, if equipped.
8. Position the oil cooler hose adapter end out of the way, if equipped.
9. Disconnect the coolant heater cord electrical connector.
10. Remove the coolant heater from the engine block.
11. Remove any burrs, sealer, or other rough spots.

1. If reusing the old coolant heater, apply thread sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent to the threads.
2. Install the coolant heater to the engine block. Tighten: Tighten the coolant heater to 50 N.m (37 lb ft).
3. Connect the coolant heater cord electrical connector.
4. For vehicles with RPO L76 (6.0L) perform the following steps otherwise proceed to step 9.
5. Position the oil cooler hose adapter end, if equipped.
6. Install a NEW oil cooler hose adapter gasket, if equipped.
7. Install the oil cooler hose adapter bolts (2), if equipped. Tighten: Tighten the bolts to 12 N.m (106 lb in).
8. Install the oil cooler hose bracket bolt (1), if equipped. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
9. Position and install the oil pan skid plate and bolts, if equipped Tighten: Tighten the bolts to 20 N.m (15 lb ft).
10. Lower the vehicle.
11. Fill the cooling system/engine block. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

1. Drain the cooling system/engine block. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
3. For 1500 series vehicles, remove the oil pan skid plate bolts and plate, if equipped.
4. For 2500 series vehicle, remove the front 2 oil pan skid plate bolts, loosen the 2 rear bolts and remove the skid plate, if equipped.
5. For vehicles with regular production option (RPO) LY6 (6.0L) perform the following steps otherwise proceed to step 10.
6. Remove the oil cooler hose bracket bolt (1).
7. Remove the oil cooler hose adapter bolts (2).
8. Remove and discard the oil cooler hose adapter gasket.
9. Reposition the oil cooler hose adapter end out of the way.
10. Disconnect the coolant heater cord electrical connector.
11. Remove the coolant heater from the engine block.
12. Remove any burrs, sealer, or other rough spots.

1. If reusing the old coolant heater, apply thread sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent to the threads.
2. Install the coolant heater to the engine block. Tighten: Tighten the coolant heater to 50 N.m (37 lb ft).
3. Connect the coolant heater cord electrical connector.
4. For vehicles with RPO LY6 (6.0L) perform the following steps otherwise proceed to step 9.
5. Position the oil cooler hose adapter end.
6. Install a NEW oil cooler hose adapter gasket.
7. Install the oil cooler hose adapter bolts (2). Tighten: Tighten the bolts to 12 N.m (106 lb in).
8. Install the oil cooler hose bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
9. For 2500 series vehicles, position the oil pan skid plate and install the 2 front bolts and tighten the 2 rear bolts, if equipped. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
10. For 1500 series vehicles position and install the oil pan skid plate and bolts, if equipped. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
11. Lower the vehicle.
12. Fill the cooling system/engine block. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Disconnect the heater cord from the coolant heater (4).
3. Loosen the coolant heater bolt.
4. Remove the coolant heater from the engine block.
5. Do not score the machined surface of the hole.
6. Grasp the plug with pliers.
7. Pull the plug from the engine block.
8. Clean the core plug hole in order to remove the following substances: Burrs Compound Paint Rough spots

1. Coat the O-ring seal and the cleaned surface of the plug opening with water resistant high-temperature grease lubricant GM P/N 9985164 (Canadian P/N 10953480), or the equivalent.
2. Tightly push the coolant heater (1) into the engine block.
3. Tighten the coolant heater bolt until both of the locking wings draw tightly against the inner wall of the engine block. Tighten: Tighten the bolt to 2 N.m (18 lb in).
4. Connect the heater cord to the coolant heater (4).
5. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
6. Inspect the cooling system for leaks.

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
2. Remove the right front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(ref-278015-S35721287192008012100000) .
3. Remove the right engine mount. Refer to «Engine Mount Replacement - Right Side»(ref-278093-S07791990302008012100000) .
4. Disconnect the engine coolant heater cord.
5. Loosen the coolant heater bolt.
6. Remove the engine coolant heater from the engine block.
7. Do not score the machined surface of the hole.
8. Grasp the plug with pliers.
9. Pull the plug from the engine block.
10. Clean the core plug hole in order to remove the following substances: Burrs Compound Paint Rough spots

1. Coat the O-ring seal and the cleaned surface of the plug opening with water resistant high-temperature grease lubricant GM P/N 1052196 (Canadian P/N 5264008), or the equivalent.
2. Align the coolant heater element to point towards the top of the engine.
3. Tightly push the coolant heater into the engine block.
4. Tighten the bolt on the engine coolant heater until both of the locking wings draw tightly against the inner wall of the engine block. Tighten: Tighten the bolt to 2 N.m (18 lb in).
5. Connect the heater cord to the coolant heater.
6. Remove the right engine mount. Refer to «Engine Mount Replacement - Right Side»(ref-278093-S07791990302008012100000) .
7. Install the right front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(ref-278015-S35721287192008012100000) .
8. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(ref-277993-S38409875582008012100000) or «Cooling System Draining and Filling (Vac-N-Fill)»(ref-277993-S13526624712008012100000) .
9. Inspect for coolant leaks.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
2. Remove the front 2 oil pan skid plate bolts, loosen the 2 rear bolts and remove the skid plate, if equipped.
3. Disconnect the coolant heater cord electrical connector.
4. Remove the coolant heater cord clip (1) from the front brake front pipes.
5. Remove the coolant heater cord clip retainer (2) from the frame.
6. Lower the vehicle.
7. Remove the coolant heater cord bolt (3) from the frame.
8. Remove the coolant heater cord from the vehicle.

1. Install the coolant heater cord to the vehicle.
2. Position the coolant heater cord clip to the frame and install the coolant heater cord bolt (3). Tighten: Tighten the bolt to 8 N.m (71 lb in).
3. Raise the vehicle.
4. Install the coolant heater cord clip retainer (2) to the frame.
5. Install the coolant heater cord clip (1) to the front brake front pipes.
6. Connect the coolant heater cord electrical connector.
7. Position the oil pan skid plate and install the 2 front bolts and tighten the 2 rear bolts, if equipped. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
8. Lower the vehicle.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
2. Remove the oil pan skid plate bolts and plate, if equipped.
3. Disconnect the coolant heater cord electrical connector.
4. Remove the coolant heater cord clip (3) from the engine harness channel.
5. Remove the coolant heater cord clip (1) from the power steering gear outlet hose.
6. Lower the vehicle.
7. Remove the coolant heater cord bolt (2) from the frame.
8. Remove the coolant heater cord from the vehicle.

1. Install the coolant heater cord to the vehicle.
2. Position the coolant heater cord clip to the frame and install the coolant heater cord bolt (2). Tighten: Tighten the bolt to 8 N.m (71 lb in).
3. Raise the vehicle.
4. Install the coolant heater cord clip (1) to the power steering gear outlet hose.
5. Install the coolant heater cord clip (3) to the engine harness channel.
6. Connect the coolant heater cord electrical connector.
7. Position and install the oil pan skid plate and bolts, if equipped. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
8. Lower the vehicle.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
2. Remove the oil pan skid plate bolts and plate, if equipped.
3. Disconnect the coolant heater cord electrical connector.
4. Remove the coolant heater cord retainer (5) from the frame.
5. Remove the coolant heater cord clip (6) from the front brake front pipe.
6. Lower the vehicle.
7. Remove the coolant heater cord bolt (4) from the frame.
8. Remove the coolant heater cord clip (2) from the chassis harness.
9. Remove the coolant heater cord clip (1) from the front spring stud.
10. Remove the coolant heater cord from the vehicle.

1. Install the coolant heater cord to the vehicle.
2. Install the coolant heater cord clip (1) to the front spring stud.
3. Install the coolant heater cord clip (2) to the chassis harness.
4. Position the coolant heater cord clip to the frame and install the coolant heater cord bolt (4). Tighten: Tighten the bolt to 8 N.m (71 lb in).
5. Raise the vehicle.
6. Install the coolant heater cord clip (6) to the front brake front pipe.
7. Position the coolant heater cord clip to the frame and install the coolant heater cord retainer (5).
8. Connect the coolant heater cord electrical connector.
9. Position and install the oil pan skid plate and bolts, if equipped. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
10. Lower the vehicle.