Water Pump: Testing and Inspection
Replace the water pump if it has any of the following defects.1. Damage or cracks on the pump body.
2. Coolant leaks; if the seal is leaking, this will be evident by traces of thick deposits of greenish-brown dried glycol running down the pump body and components below. A thin black stain below pump weep hole is considered normal operation.
3. Excessively loose or rough turning bearing.
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 green/brown engine coolant is evident on water pump body from the weep hole (shaft seal failure). Be sure to perform a thorough analysis before replacing water pump.