Raw Water Pump Leak at mounting flange?

Jun 2, 2014
602
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
My bilge is normally very dry, so if there's any sign of water something isn't right.

After working on replacing my impeller in the Oberdorfer pump and getting that working 100%, I was inspecting for leaks and noticed that there was water dripping from the lower mounting screw on the flange the mounts to the engine block. As you'll see in the photo, it looks like this is not a new problem, there's lots of visible corrosion there.

So, my questions are... Is this water likely coming from the inside of the pump?
There's no water of any kind between the pump flange and the engine, correct? - Meaning, I could remove the pump completely from the block and there is no water or fluid between the two, right?

IF the water IS coming from the inside of the pump, that means I've got a bad seal somewhere inside the pump, right? And I will likely have to get some new parts for the inside or take it to someone?
 

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Jun 2, 2014
602
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
I called a local shop and they told me that the seals are just worn and there's a weep hole right there that is supposed to allow it to drip out.
So, now that the pump is otherwise working, what seals do I need to replace to get this water tight again?
 
Jun 2, 2014
602
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
I know I'm still talking to myself here, but wanted advice before I ordered something...

This place has GREAT prices on entire pumps and parts:
http://www.downwindmarine.com/Oberd...eller-Pumps-Universal-Engines-p-91002307.html

After reading about rebuilding, I know I'll need the lip seals, $30. I probably need the carbon bearing $14.25, and I really should get a new shaft $34.50.
So, now I've spent $80, and still need to spend a few hours taking stuff apart, reassembling, etc. They have the entire pump for $210! Almost seems worth it.

But, I have to save money everywhere I can right now, so maybe I don't need a new shaft, but do I need a new carbon bearing? If not, then I can get away with $30 to fix the leaky pump, and that's worth it to me to spend my time instead of buying a new pump. But I have a feeling you'll tell me to get the carbon bearing too. back up to $45. I guess its still worth it.

Is there a gasket between the flange and the block?? I don't see a part for that anywhere. - NM, just found it, and the local store has it. I'll just pick it up when I get the new shaft seals.
 
Last edited:
Sep 1, 2013
53
catalina 30 suttons bay
I bought/ installed a new unit when mine began to weep. 200 is cheap for the whole bolt on unit, the entire swap took maybe 15 min.
 
Feb 26, 2004
23,102
Catalina 34 224 Maple Bay, BC, Canada
jonelli,

Glad the wealth of information AI keep linking you to has helped. n Good for you on the faceplate.:dance::dance::dance:

There is great article about how to do just that to an Oberdorfer in the wiki.

Rebuilding an OBERDORFER Raw Water Pump with Flix http://c34.org/bbs/index.php/topic,6766.0.html
 
Jun 2, 2014
602
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
Yep. Been reading that one and all the others I found. I wish I could just pop for the new pump right now and I am tempted, but gonna just try to seal this one up first. It should be doable.
 
Jul 21, 2013
333
Searching for 1st sailing boat 27-28, 34-36 Channel Islands, Marina Del Rey
You will gain a wealth of experience by rebuilding the pump and get to know the systems. Include the bearing in the rebuild, post lots of pictures.
 
Oct 5, 2010
322
Catalina 30 mkII St. Augustine
I know I'm still talking to myself here, but wanted advice before I ordered something... This place has GREAT prices on entire pumps and parts: http://www.downwindmarine.com/Oberdorfer-Model-202M-Rubber-Impeller-Pumps-Universal-Engines-p-91002307.html After reading about rebuilding, I know I'll need the lip seals, $30. I probably need the carbon bearing $14.25, and I really should get a new shaft $34.50. So, now I've spent $80, and still need to spend a few hours taking stuff apart, reassembling, etc. They have the entire pump for $210! Almost seems worth it. But, I have to save money everywhere I can right now, so maybe I don't need a new shaft, but do I need a new carbon bearing? If not, then I can get away with $30 to fix the leaky pump, and that's worth it to me to spend my time instead of buying a new pump. But I have a feeling you'll tell me to get the carbon bearing too. back up to $45. I guess its still worth it. Is there a gasket between the flange and the block?? I don't see a part for that anywhere. - NM, just found it, and the local store has it. I'll just pick it up when I get the new shaft seals.
Put a new pump on and rebuild the old and then you will have a spare.
 
Feb 26, 2004
23,102
Catalina 34 224 Maple Bay, BC, Canada
Pump sources

www.depcopump.com, too

I know I'm still talking to myself here, but wanted advice before I ordered something...

This place has GREAT prices on entire pumps and parts:
http://www.downwindmarine.com/Oberd...eller-Pumps-Universal-Engines-p-91002307.html

After reading about rebuilding, I know I'll need the lip seals, $30. I probably need the carbon bearing $14.25, and I really should get a new shaft $34.50.
So, now I've spent $80, and still need to spend a few hours taking stuff apart, reassembling, etc. They have the entire pump for $210! Almost seems worth it.

But, I have to save money everywhere I can right now, so maybe I don't need a new shaft, but do I need a new carbon bearing? If not, then I can get away with $30 to fix the leaky pump, and that's worth it to me to spend my time instead of buying a new pump. But I have a feeling you'll tell me to get the carbon bearing too. back up to $45. I guess its still worth it.

Is there a gasket between the flange and the block?? I don't see a part for that anywhere. - NM, just found it, and the local store has it. I'll just pick it up when I get the new shaft seals.
 
Jun 2, 2014
602
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
UPDATE:
It stopped leaking... lol.
But I know it must leak once in a while because of the visible evidence. My theory is that since messing around with the impeller so much I must have disturbed the old seals, and eventually it settled back into whatever seal/groove it was in.
So, I will not be rebuilding it just yet. I'm going to keep the parts though. I think I'm going to order a replacement NEW pump later this year, swap it out when I'm not sailing or using the boat, then rebuild the old one and keep it as a spare.
So, you'll have to wait a while for the pictures.