Mercury 6L2Z-8501-A Water Pump Assembly

Water pump failure can cause engine damage due to overheating. If the pump seal fails, coolant leaks from the front cover in V6 models or the water pump housing in V8 models. The water pump is located in the front cover for V6 engines and in a housing in the engine block for V8 engines. Water pumps have weep holes that can be checked for leaks with a flashlight. If there's heavy brown staining or visible coolant, the pump needs replacing. If the pump shaft bearings fail, a howling sound may be heard. Shaft wear can be felt by rocking the water pump pulley. Don't confuse drivebelt slippage, which causes a squealing sound, with pump bearing failure. A quick pump check is to turn on the heater; if the pump is failing, it won't circulate hot water efficiently.

If the seal has leaked, it should be very apparent when you inspect for coolant residue or dried coolant tracks around the weep hole(s).

Remove the thermostat housing, disconnect heater hoses and the expansion tank hose from the outlet tube, and clean the O-ring surfaces.

Disconnect the negative battery cable and drain the cooling system.Remove the drive belt and the bolts securing the water pump pulley.Remove the bolts holding the water pump to the engine block and carefully pull the water pump straight out from the block.Lubricate the O-ring seal on the new water pump with Merpol or equivalent before installation.Reverse the removal steps, ensuring that all fasteners are tightened to the specified torque.Refill the cooling system.

After replacing the water pump, you should refill the cooling system and check the drive belt tension. Run the engine and inspect for leaks.