Procedures
WATER PUMP
Inspect and 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 shaft seal is leaking, this will be evident by traces of thick deposits of dried glycol running down from the pump primary weep passage located behind the pulley. A thin black stain below the pump primary weep hole/passage is considered normal operation.
NOTE: It is normal for the water pump to weep a small amount of coolant from the primary weep hole (black stain at weep passage). 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 primary weep passage. This indicates a shaft seal failure and pump must be replaced. If this condition is found, clean the primary weep passage of debris. Be sure to perform a thorough analysis before replacing water pump.
3. Impeller rubs inside of cylinder block.
4. Excessively loose or rough turning bearing.