Impeller Hell

[Steve Linsk]

I spent last Sunday in "impeller Hell" trying numerous ways to remove my water pump impeller from the shaft. After much pain, pounding, and trips to Home Depot to Jerry-rig a clamp assembly, I was successful at removing the old impeller. Now... I am trying to install the new impeller on the (cleaned up) old shaft and the impeller hole seems too small for the shaft. Am I doing something wrong or is it supposed to be this difficult. The Universal 25 owner's manual says the impeller should "slip off" the shaft. No way... Any suggestions on what to do here?

 

[Robert Moretti]

impeller should go on with a little grease

Having just changed the impeller on my M25 Universal with an Oberdorfer water pump, I can tell you that it should not be the struggle that you have described. First, make sure that you have the right impeller for your water pump. Universal M25 engines on Catalinas may be using one of three different water pumps (Oberdorfer, Sherwood, etc.). It is the identity of the water pump that is important. Once you know you have the right impeller, grease the pump shaft with a little Teflon grease or something similar. Make sure the impeller mount opening is lined up properly with the shaft, and it should go on fairly easily.r-moretti@northwestern.edu