M25-XP Oberdorfer Raw Water Pump is dripping oil at the base

Jops

.
Sep 19, 2020
14
Catalina Catalina 36 San Diego
M25-XP Oberdorfer Raw Water Pump is dripping oil at the base. Can I just order a new mounting gasket or do need a whole rebuild kit?
 

Tsuru

.
Sep 4, 2019
6
Oyster 435 Hood River
If the oil is dark engine oil. You'll only need a new gasket. Anything other than engine oil, rebuild it.
 
  • Like
Likes: kloudie1
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
If the oil is coming out of the flange mounting it to the front cover, you should be ok with a new paper gasket. It is more likely that the oil is coming out of the weep hole about 1/2" out from the flange. If that is the case, your problem is the oil seal on the shaft. The pump has two back-to-back seals. The one towards the engine seals the engine oil and the one towards the impeller seals the seawater. There is a weep hole between the two seals to let you know when there is a seal failure. Mine started leaking and I hoped to do a rebuild but once disassembled I found that the shaft was too badly scored to rebuild so I needed a full replacement.
 

Attachments

Mar 6, 2008
1,078
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
Replacing seals is easy and inexpensive. If you have 200 hours on it, it is time to order the kit that includes a new impeller for $65.00.
Visit Sail La Vie | 1999 Catalina 36 MK II for how to with images and view the album. Avoid performing seal change the way that the manufacturer showed you on their YouTube video. I used steering wheel puller to remove and insert the new seals without damaging them.
 
  • Like
Likes: DaddioLI
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
This home-made tool helps remove the old seals. One of the on-line videos showed it, so I can't take credit for it.
Good point (pi!:)). A description of how to make one is in my link, too.
 

Jops

.
Sep 19, 2020
14
Catalina Catalina 36 San Diego
Thanks so much for the help. This gives me lots of info to start with. Happy New Year.
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
I would suggest that the first thing you do is tear down the old pump as I showed in my photo to see what condition the parts are in. If the shaft and housing are in good condition it is a simple pump to rebuild. You can also replace the shaft but I found that once I got to that point, the difference in cost of the replacement parts vs replacing the whole pump prompted me to do the whole pump. There is one added benifit to full replacement if you have the older pump with the paper gasket for the impeller cover. The new pumps are sealed with an o-ring which makes changing the impeller much simpler.