leak at waterpump

[Jeff Kaplan]

Yesterday, fire up the diesel in preperation of next weeks launch. Prior to this, had mechanic install a new impeller and gasket on oberdoffer 4 bolt waterpump on m25. Engine fired right up and was pumping fine. Removed ladder and stairs to check for any leaks from pump, filters,ect. and noticed a drop of water leaking from, not the impeller face plate, but thru the open slot at the bottom of the pump. Only a drop at a time, not a flow,and no temp. rise. I called the mechanic to explain, but he hasn't got back to me yet. Question,is this going to be a problem or should I start to think of replacing the pump, or is there a seal that can be replaced. All replys appreciated. Thanks...Jeff

[Ron Hill]

Jeff : There are two lip seals in your Oberdoffer, one to keep the the oil in the engine and one to keep the water in the pump.  They are on either side of the weep holes.
I've written a couple of Mainsheet tech note articles on how to change them.  Read the last article which specifically deals with the changing of the lip seals - sorry I'm out sailing and can't give you the article's date.

The first thing that you need to do is order a couple of seals from DEPCO.

If you're in a hurry and have a close by Universal dealer they might stock those seals and your mechanic might be able to change them for you.

A few thoughts

[pablosgirl]

Hi Jeff,

Ron's article is also posted in the Tech Wiki under the engine section too.

Paul

[Jeff Kaplan]

Thanks for the info. Brought pump to Hanson marine,in marblehead,Ma. Universal dist., had 2 new seals installed. Re-installed pump, fired her up, no leaks and pumping like a champ. In head, found one of the copper lines to the sink fawcet split, pissing water everywhere. Ended up cuttting all tubes to remove. Got 2 pipe plugs and sealed off the lines till a replacement can be ordered, saw one on Catalina direct. That repair can be done at the mooring. If it isn't one thing, it's another...Jeff

[scotty]

I just bought a new Oberdoffer pump and am installing it tomorrow.  I checked the package today and it does not include a gasket.  I assume that there should be a gasket between the pump and the engine.  I looked on the internet (and the wiki, etc.) but could not confirm this.  Does anyone out there know if there should be a gasket?  If I make my own, what thickness of material should I use?  Thanks.

[learjetzz]

Changed a buddy's impeller. Had no gasket, did not leak ,but did install a wax paper stlyle gasket with a very light smear of D-C compound on both sides of gasket. Ops checked it a slip (F&R) for appx. 30 min. no leaks. B.T.W. check for trueness on cover you may have to lap to be sure it isnt warped.

[Jeff Kaplan]

Scotty, get a gasket before installing pump. Look at the old pump you took off, it may still be attached. Mine was still good so I reused it. Metal to metal does not make a great seal. The gasket material on mine was very thin, so if you make one, cut to size and install...Jeff

[scotty]

Thanks you Jeff, that's what I thought.  Thanks for the imput on the cover, Learjetzz.

[Stu Jackson]

Scotty, get a few paper bags, not the heavy supermarket kind, but smaller ones, but not the thinnest.  You can make your own gasket, or call Depco and get one or two or three.  Always good to have around.

[Ron Hill]

Scotty : There is a thick gasket between the Oberdoffer and the engine.  I always used the old one over again.  It seals the oil in the engine.

The paper thin gasket is the one between the Oberdoffer face plate and the pump housing.  A few thoughts.

[scotty]

The pump went on great.  I bought a new gasket.  Remembered Grandfather's advice: "Do it right the first time".  Interesting that the new pump wouldn't quite fit on - there is a small finger-like piece sticking out from the block that the new pump hung up on.  I got a grinder and took off about 1/16" off the new pump and then in went on just fine.  Ran the boat about an hour and it runs well, no leaks.  The hoses are OK for now, but I plan to replace them in a month or so.