Examination
A faulty water pump can cause the engine to overheat and fail (the engine is not cooled by the circulating coolant flow).
The performance of the water pump can be checked in three ways without removing it from the engine. If the pump is defective, it must be replaced or repaired.
Warm up the engine to operating temperature and pinch the upper radiator hose.
If the pump is working properly, then when the hose is released, a push will be felt from the pressure of the coolant.
Check holes are provided in the water pump housing for fluid leakage. If the pump is leaking, a small amount of leakage will occur through these holes. To check for pump leakage, remove the lower timing belt cover and, from the underside of the vehicle, illuminate the lower part of the pump housing with a powerful lamp.
If the water pump shaft bearings are out of order, then a sharp squealing sound will be heard from the front of the engine. Shaft wear is felt by play when the pump pulley swings up and down.
All parts of the pump are interchangeable, however, repair work should be entrusted to a specialist or handed over to a service center, as special fittings will be required.
Removal and installation
Read the warning in sec. 2.
Drain the coolant.
Remove the toothed belt guards and toothed belt. Remove the toothed belt tensioner pulley.
Disconnect the inlet hose from the water pump.
Loosen the water pump mounting bolts.
Pic. 5.7. Water pump: 1 - toothed belt; 2 – the top casing of a gear belt; 3 - drive belt; 4 - pulley; 5 – the bottom casing of a gear belt; 6 - hose; 7 - tensioner roller; 8 - water pump; 9 - gasket
Using a large screwdriver or a suitable size spatula, separate the water pump while jiggling it to disengage the pump gear (pic. 5.7).
After shifting the water pump forward, turn out the bolts and disconnect the inlet pipe.
Remove the water pump from the engine compartment.
Thoroughly clean the contact surfaces of the pump from gasket residues. Inspect and clean the gasket groove.
Lubricate the O-ring with petroleum jelly and place it in the groove. Lubricate both parts of the gasket with sealant before installation.
Reinstall the water pump and attach the inlet pipe. Tighten the two pump mounting bolts by hand.
Install the remaining bolts and cross-tighten them to the required torque.
Connect the inlet hose.
Install the toothed belt and belt guards.
Pour antifreeze into the cooling system.