Water Pump: Service and Repair
REMOVAL PROCEDURECAUTION: Refer to Battery Disconnect Caution in Service Precautions.
1. Disconnect the negative battery cables.
2. Drain the coolant from the radiator. Refer to Draining and Filling Cooling System.
3. Remove the fan shroud.
^ For the upper shroud, refer to Fan Shroud Replacement (Upper).
^ For the lower shroud, refer to Fan Shroud Replacement (Lower).
4. Remove the drive belt. Refer to Drive Belt Replacement (6.5L Drive Belt) in Engine.
5. Remove the fan and fan clutch, Refer to Fan Clutch Replacement (5.0L, 5.7L and 6.5L).
6. Raise the vehicle. Support the vehicle with safety stands. Refer to Vehicle Lifting.
7. Remove the following vacuum pump components. Refer to Vacuum Pump Replacement in Vacuum Pumps:
7.1. The mounting bracket nuts
7.2. The bolt securing the vacuum pump bracket and the generator
7.3. The vacuum pump and the bracket
8. Remove the power steering pump. Lay the pump aside.
9. Lower the vehicle.
10. Disconnect the lower radiator hose from the coolant pump. Refer to Radiator Hose Replacement (6.5L Diesel).
11. Disconnect the bypass hose from the coolant pump.
12. Remove the bolts, the studs, the coolant pump backing plate and the coolant pump.
13. Remove the bolt from the rear of the coolant pump backing plate.
14. Remove the coolant pump and the gasket from the backing plate.
IMPORTANT: All of the flanges must be free of oil.
15. Clean the following mating surfaces:
^ The coolant pump
^ The coolant pump backing plate (both sides)
^ The engine block
INSTALLATION PROCEDURE
1. Install the gasket.
2. Install the coolant pump to the coolant pump backing plate. Refer to Water Pump Removal in Engine.
NOTICE: Refer to Fastener Notice in Service Precautions.
3. Install the bolt.
^ Tighten the bolt to 23 Nm (17 ft. lbs.).
4. Apply anaerobic sealer GM P/N 12346286, or equivalent to the coolant pump backing plate. The sealer must be wet to the touch when tightening the bolts.
5. Install the coolant pump and the coolant pump backing plate to the engine.
6. Install the bolts and the studs.
^ Tighten the bolts and the studs to 42 Nm (31 ft. lbs.).
7. Connect the bypass hose.
8. Connect the lower radiator hose, Refer to Radiator Hose Replacement (6.5L Diesel).
9. Install the power steering bracket and the pump.
10. Raise the vehicle.
11. Install the vacuum pump and the bracket.
12. Install the bolt that holds the vacuum pump and the generator.
13. Lower the vehicle.
14. Install the fan and fan clutch assembly and the coolant pump pulley. Refer to Fan Clutch Replacement (5.0L, 5.7L and 6.5L).
15. Install the drive belt. Refer to Drive Belt Replacement (6.5L Drive Belt) in Engine.
16. Install the fan shroud.
^ For the upper shroud, refer to Fan Shroud Replacement (Upper).
^ For the lower shroud, refer to Fan Shroud Replacement (Lower).
17. Connect the negative battery cable.
18. Fill the surge tank with coolant. Refer to Draining and Filling Cooling System.
19. Start the engine. Run the engine with the surge tank cap removed, until the upper radiator hose becomes hot. (This indicates that the thermostat is open).
20. While the engine is running at idle speed, add coolant to the surge tank until the level reaches the FULL mark. Refer to Draining and Filling Cooling System.
21. Install the surge tank cap. Make sure the cap\ arrows line up with the overflow tube.
22. Inspect the cooling system for leaks.