Oberdorfer Raw Water Pump & Rebuild Info

[Rick Allen]

After noticing some water in the bilge yesterday while motoring at 2500rpm in calm seas, I checked the engine (25xp) and found salt water pouring out of the raw water pump weep holes.  Apparently it's been happening to some extent for awhile, at least since I've been in there 6 months ago.  Since the water is coming from the weep holes and the pump is pumping fine, I'll assume that the seal has gone bad. (Thanks Stu for the critical upgrades thread!!).  My question is, should I try to replace the seals myself or take it off and have the pump professionally rebuilt or just buy a new pump. (Torresen, $267.00, I'll also check DEPCO). Does anyone know of a good supplier/rebuilder in the SF Bay Area? Also, because of the corrosion to the area below the pump, I again assume I should clean with wire brush and, of course, repaint unless there's a critical step I'm missing.  I'll also replace all hoses and clamps. I've also seached "Oberdorfer" and found some good info here.

Thanks in advance for any advise!

Now I'll lift my skirt here and show you pictures and the damage below the pump.  Like Stu say's, "A picture is worth a thousand words".  See the pictures here:
http://public.fotki.com/Sailorick/sv_painkiller/water-pump/

Thanks Again!

Rick

[Stu Jackson]

Rich, I'll bet KKMI will redo your pump seals for you.  No need to buy a new pump.  Or Sea Power in Oakland is the local Universal supplier, who will do the seals or sell them to you.  Only reasons I bought a new pump in 1998 was 1) it cost as much to redo the seals as a new pump; 2) I didn't know any better.  You can do it if you know how, I've read about it, haven't done it myself, Calder has a good description.

Say it after Rich: "I promise to check my engine when it's running more than once every six months."

[Rick Allen]

"I promise to check my engine when it's running more than once every six months."

What would I do without you Stu!

[PK]

Some thoughts from my experience rebuilding a Sherwood pump a few months ago... 
The seals will probably be expensive if you get them thru a marine distributor like Torresen. Mine was about $35.
If the seal was bad, your bearings are probably bad as well and will need to be replaced.  I got mine from a local supply shop and only paid a couple of dollars each for them.
My seal was a PITA to remove, basically had to destroy it to get it out.
If you don't have a fancy tool to press in seals, I would find a piece of metal pipe that just fits the outside rim of the seal, set it on the rim of the seal and use a mallet to uniformly smack it into place.
Remember that you'll probably have to replace the gaskets between the pump body and engine block, and the gasket between the cover and the pump body.  Those are cheap and easy.
If you can get someone to rebuild it for around $100, I'd let them deal with it.  Or if you just want to do it yourself, it isn't that complex, especially if you have some mechanical skills or, like me, find some friends with some skills to help.
Good luck.  It feels good to have a rebuilt pump that doesn't leak.

[Ken Juul]

The question can't be answered until you get the pump open.  Is the shaft reusable?  Any other corrosion damage caused by the raw water?  If you remember the thread a few months ago....are you sure the oil seal is still working or do you have water in your oil?

If all is fine, the rebuild itself isn't that hard.  A normal socket set should have the correct size to tap the seals in place.  Don't cheap out.  Do a complete rebuild, both seals and all gaskets.  Unless you want the opportunity to do it again in a few months.

[Ron Hill]

Rick : I just looked at your pictures - WOW!!.  Think you'd better start checking your oil every week and start looking around your engine for existing & potential problems.

Look in the Mainsheet tech notes and you'll find an article I wrote on rebuilding your Oberdoffer yourself.  I bought an extra pump and when a problem came up I replaced it with the extra that was ready to go. Then took the old pump back home and rebuilt it. 
I'm going to guess that you'll probably need a new shaft also.  I'd get all of that salt off of everything and keep your fingers crossed.  As I wrote many years ago "wouldn't it be ashame that a C34 owner had to replace the oil pan just because the raw water pump was leaking and the salt water ate thru the metal!".

A few thoughts. 

[Tom Soko]

Rick,
You might want to consider replacing the forward stbd motor mount as soon as you can.  Ron Hill wrote an excellent article a number of years ago about doing it without removing the engine. 

[Ron Hill]

Rick : Tom is correct on that engine mount. 
You need to get all of that salt water corrosion off of the engine and inspect every piece that it was on, i.e. the fuel filter bracket etc. etc.

[Rick Allen]

Thanks all for great suggestions and advise!  It's going to be a busy weekend!!  I'll also post some pictures of the repairs.

[Michael Shaner]

One can do a complete rebuild of an "old sherwood" for less than a hundred bucks in the marina parking lot with a vice and a socket set (Tom, still got yours? )

Never rebuilt an Oberdorfer, but if its anything like the new Sherwoods, it could be a bit challenging. As PK mentioned, there appears to be a lot of corrosion that develops in the newer pumps making the pump hard to disassemble...particularly the seals (why to do they put all that ferrous metal in there?!?!). We couldn't get the 10 year old seals out of a "new sherwood" in a 1.5 ton press...until it simmered for a couple hours in PB blaster followed by several smacks with a 6 pound mallet. To echo Ken, plan to replace everything in there. After disassembly, there wasn't one internal part of that pump that could be reused...coulda been that mallet though... 

Good luck Rick!!

[pablosgirl]

Well after looking at Rick's pictures, I went down to the boat and started the engine and then took the covers off and just watched the engine run for a while to see if any water appeared.  After about 5 minuets at idle a small drop appeared in the weep hole.  Not much of a leak, but a leak just the same.  So I think I will rebuild my pump too.  Where do I order the Oberdorfer parts from?

[Stu Jackson]

DEPCO - search for the phone # from earlier posts

[David Sanner]

I had Carl Stirtz in Oakland rebuild my pump for a very reasonable price.
Basically all you need is a decent press to do the job.  If I recall he also
smoothed out the pump's face plate on his bench belt sander as it has
some slight wear marks/grooves.

[wiki]Engine_Rebuild[/wiki] has some photos of my pump rebuild.

[lucky]

Look at img #8 my oberdorph has the weep hole on the bottom,this one is at 2 oclock. I don't think there are two weep holes,I'd sure have oil sample taken
Al
Lucky hull #13
1986 34

[lucky]

Just got back from Lucky,I was wrong about weep hole at 2 o clock I have the same thing,but also weep hole on the bottom.The bad news is I found red oil under the engine.
Al
Lucky hull#13
1986 catalina