Detecting Water Pump Failure

DETECTING WATER PUMP FAILURE (ENGINE OFF)

Check for shaft seal failure by carefully inspecting the water pump weep hole. When a pump is new, some seepage is normal in the initial hours of operation as the seal seats. Other than minor seepage, any leakage that occurs is due to seal failure and the pump needs replacement. There may be a tell tail trail of rust, calcium, and coolant deposits on the water pump housing with the weep hole as the origin.

Detect a worn water pump bearing by checking for side-to-side play at the shaft. There should be no perceptible play as you apply hand pressure to the shaft. Accelerated bearing wear is characterized by screeching or rumbling noises coming from the water pump housing. Turn the water pump pulley and listen for unusual noises. Also, feel for smooth rotation as the pump is turned. If any of these conditions exist, the bearing is worn out and the pump should be replaced.

In general, many things can cause a water pump failure including: Defective, crooked or unbalanced fans, defective or unbalanced fan clutches, excessive (too-tight) fan belt tension, dirty cooling systems, insufficient clearance between fan and shroud or radiator, and loose or broken motor mounts to name a few. Everything should be checked to avoid a premature water pump failure.