Water Pump: Inspection

WARNING: This page is about a different variant/trim than selected.

Check the water pump bearing for smooth rotation.
Check the water pump pulley for abnormalities.
Make sure the impeller is not deformed or damaged.
Inspect the clearance between impeller and pump case.
Clearance between impeller and pump case:

Standard value

0.5 - 1.5 mm (0.020 - 0.059 in)

Fig 1: Measuring Clearance Between Impeller And Pump Case
Courtesy of SUBARU OF AMERICA, INC.
After water pump installation, check the pulley shaft for engine coolant leaks and noise. If leaks or noise are noted, replace the water pump assembly.