Sea Water Pump Impeller Almost Froze to Housing

[Bob & Sue]

In Feb of this year I replaced the sea water pump with my spare pump that had a new mercruiser impeller kit that I installed plastic housing, impeller, wear plate, o-rings and bolts. Ran fine for about 20 hours one afternoon loading the boat at the marina for shrimp season started the engine and the serpentine belt squealed like crazy shut the engine down loosened the belt tried turning the sea water pump it was tight then it freed up and we put almost 30 more hours on it without any problems. Yesterday I pulled the pump off and put the other one on after rebuilding it. When I got home I tried turning the pump it was almost frozen it took about 20 minutes to get the impeller out after inspecting everything the only thing I can see is a lot of wear on the wear plate as much as the one I replaced with 300 hours on it and the impeller looked good but felt kind of sticky like it was deteriorating. When I put the impeller in I used some 30 weight oil on it to get it to slide into the housing on the one I just installed I used dish soap. I have read different opinions on using oil or grease on impellers most mechanics have used both. Any ideas what caused the impeller to get so tight.

 

[Bt Doctur]

oils and greases can destroy the rubber or cause it to swell.better off with dish or K-Y lubricant

 

[Bob & Sue]

oils and greases can destroy the rubber or cause it to swell.better off with dish or K-Y lubricant

Well I guess this is a good lesson I just read the service manual it states no oil use soap and water. Next time I think I'll read the manual first maybe that's why they make them.
Thanks