Water Pump: Inspection

Fig 1: Inspecting Water Pump

Courtesy of DAIMLERCHRYSLER CORP.

NOTE: It is normal for the water pump to weep a small amount of coolant from the weep hole (black stain on water pump body). Do not replace the water pump if this condition exists. Replace the water pump if a heavy deposit or a steady flow of engine coolant is evident from the weep hole. This indicates a shaft seal failure and pump must be replaced. Be sure to perform a thorough analysis before replacing water pump.

Inspect and replace the water pump if it has any of the following defects:

Damage or cracks on the pump body (1).
Coolant leaks; if the seal is leaking, this will be evident by traces of thick deposits of dried coolant draining from the pump weep hole. A thin black stain below pump weep hole/passage is considered normal operation (2).
Impeller rubs against the engine front cover (3).
Excessively loose or rough turning bearing (3).