Water Pump: Inspection

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

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

Standard

0.5 - 1.5 mm (0.020 - 0.059 in)

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