Water Pump: Service and Repair

Water Pump Replacement (L18)

Removal Procedure




1. Drain the cooling system. Refer to Draining and Filling Cooling System Draining and Filling Cooling System.
2. Remove the fan and clutch. Refer to Fan Clutch Replacement (L18) Service and Repair.
3. Loosen the outlet hose clamp (4) at the water pump.
4. Remove the outlet hose (3) from the water pump.




5. Reposition the bypass hose clamps at the water pump and coolant crossover.
6. Remove the bypass hose.




7. Remove the water pump bolts.
8. Remove the water pump and gaskets. Discard the gaskets.
9. Clean and inspect the water pump. Refer to Water Pump Cleaning and Inspection (C/K) Water Pump Cleaning and Inspection (G/C3500HD/Medium Duty) in Engine Mechanical - 3.1 L Unit Repair.

Installation Procedure




1. Install the water pump and new gaskets.
Notice: Refer to Fastener Notice in Cautions and Notices.

2. Install the water pump bolts.

Tighten the water pump bolts to 50 Nm (37 lb ft).




3. Install the bypass hose.
4. Position the bypass hose clamps at the water pump and coolant crossover.




5. Install the outlet hose (3) to the water pump.
6. Tighten the outlet hose clamp (4) at the water pump.

Tighten the outlet hose clamp to 5 Nm (44 lb in).

7. Install the fan and clutch. Refer to Fan Clutch Replacement (L18) Service and Repair.
8. Fill the cooling system. Refer to Draining and Filling Cooling System Draining and Filling Cooling System.