Rebuild water pump

Apr 17, 2013
153
Catalina 310 57 Pompano Beach, FL
Recently changed out the stock Sherwood water pump on the Universal 25XPB with the Oberdorfer N202M-908. After 675 hrs it started leaking at the weep holes, bought another pump since we were in the Bahamas and installed it everything OK. Looking at rebuilding the failing pump, there are 2 seals which I have found can be purchased from numerous suppliers for around $26 each. First it seems it did not have that many hours on it before it started to fail, spoke to a person at Depco and he agreed. My questions are has anyone rebuilt this pump and what method did you use to extract the seals. The shaft looks fine and I can see that the front seal is torn. I did put a screwdriver in the pump to try and tap out the rear seal, I may have torn the seal myself but I don't think so. I assume that the forward seal is installed form the front and the rear seal from the back. Any help would be appreciated.

Thanks,
Mark
 
Jun 4, 2004
292
Hunter 49 123
I just went thru this issue for my FP/Kubota engine. I got darwings, I called Johnson, installed lip seals per directions and finally I send it to a pump repair facility and they concluded that the pump could not be rebuilt. Get a new pump!
 
Apr 17, 2013
153
Catalina 310 57 Pompano Beach, FL
Thanks for your reply, the one that Maine Sail is discussing is a different type of pump this one has no bearings only two lip seals which are pressed in
 
Nov 6, 2006
9,885
Hunter 34 Mandeville Louisiana
bearings/bushings.. think about changing them .. Lots of times, the bushings will wear from the shaft pushing away from the eccentric by the impeller.. making the new water seal a very short lived item. if you can wiggle the shaft in the bushings, they should be replaced.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Yes, I have rebuilt the oberdorfer. After about 700 hours the seals went. Actual just the one but replaced both. What I found was it still leaked after. Then I took a real close look at the shaft and discovered that was the problem. I polished the shaft with some hi grit wet sand paper. I have another 700 hours with no issues.

As far as rebuilding the pump, look at the C34 tech wiki. They have a great write up. The rebuild involved making a took from an old Alan wrench.
 
Apr 17, 2013
153
Catalina 310 57 Pompano Beach, FL
Thank you, I will look at the C34 tech wiki. I will look at the shaft again and polish it. Are you back in the states or still cruising.

Thanks,
Mark
 
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
Anybody got the part number for the impeller for the Oberdorfer pump (N202M-908)? Thanks.

Cheers,
Jim (Hull #178)
 
Apr 2, 2011
185
Catalina 27 Niceville, FL
My experience with Sherwood pumps is the water seal is very difficult to remove without a special tool. Unless you are very lucky, you will scour to bore and ruin the pump if you try to remove it. I would trash the Sherwood and stick with Oberdoffer pumps.