Water Pump: Service and Repair

Coolant Pump, Replacing (M70 engine)




M70 engine coolant pump and thermostat housing.
- Drain cooling system as described earlier.


WARNING: Allow cooling system to cool before opening or draining cooling system.


- Raise car and support in a safe manner.


WARNING: Make sure the car is stable and well supported at all times. Use a professional automotive lift or jack stands designed for the purpose. A floor jack is not adequate support.


- Remove tan clutch assembly and fan shroud.


NOTE: The radiator cooling fan nut (32 mm wrench) has left-hand threads.


- Working below car, remove engine splash shield.




- Remove crankshaft vibration damper mounting bolts (arrows) and remove vibration damper on M70 engine.
- Remove water pump pulley and drive belt.
- Remove coolant hoses from coolant pump/thermostat housing. Remove pump mounting bolts (qty. 6).




- Uniformly screw three MS bolts (arrows) into tapped holes in coolant pump housing to push coolant pump out of mounting block.
- Installation is reverse of removal.
+ Transfer thermostat from old pump using a new 0-ring. Use HWB© lubricant or equivalent to lubricate 0-rings.
+ Fill system with coolant and bleed.

Tightening Torques

- Coolant drain plug to engine block 25 Nm (18 ft-lb)
- Coolant pump to timing chain cover 10 Nm (89 in-lb)
- Coolant pump pulley to coolant pump 10 Nm (89 in-lb)
- Thermostat housing to coolant pump 10 Nm (89 in-lb)
- Vibration damper to crankshaft hub (M8) 22 Nm (17 ft-lb)