Raw Water Pump Impellers

Changing Raw Water Pump Impellers

This is a tough job on 'twins', and it's even tougher if you put the pump housing in backwards. (Ah-hem!) The impeller has to 'screw into the housing' in one direction as well. The below photo and diagram show how the parts go, but a smart mechanic marks the parts before taking them apart. (Ah-hem!) The impeller shown had at least three years running on it and was still good. Best to change them BEFORE they start throwing blades. If yours is chewed up, be sure to backflush the oil cooler, to remove the impeller pieces--or else the new one will be destroyed. (Thanks to Norm for the second photo below.)