leaking Oberdorfer

[Loren Beach]

New problem today. (Sigh)
Friday I did the oil and filter change and put in the new impeller and ran it for 20 minutes. All was well. Today I ran it in gear after checking the level in the transmission. (Oddly enough I did have to add about 1/4" of pink ATF. Cannot feel any seepage under the trans or at the bell housing... I guess that I shall just have to check it often.)

Immediately after starting up the little raw water pump started a slow dribble of water right behind the front part of the casting. Rats.
The front plate with its new paper gasket is dry, FWIW.

After 20 years and 1880 hours I suppose it has a limit to its life, but we have plans to go on vacation in June (Note to self: man proposes, God disposes...)

When I had the pump shaft out to install the new impeller I did notice that the shaft was scored - and per the diagram there is a sleeve inside the pump housing. The oil seal in the back must be fine as ever; no seeping of oil.
Some years ago I had a mechanic friend lap the front plate to get the grooves out so it would seal and pump better.
**Sidebar: I have been cursing that front circlip annually, since 1995, BTW. Sheesh, that little piece of spring steel is hard to reinsert...
Without a shop or press, is the normal procedure just to buy another pump? Do people normally rebuild these things? Or, as is often the case, does the cost of a shaft, bushing, and labor equal the price of a whole pump?

Advice greatly appreciated.
Thanks!
Loren
ps: I just ran across this older thread. http://www.ericsonyachts.org/infoexchange/showthread.php?t=6513&highlight=oberdorfer
Perhaps replacement is a reasonable option. I shall check pricing on a new one, just in case.

 

[Rhynie]

Loren,
I think that it is Moyer Marine (Google it) that carries a rebuild kit. It is not a major deal, common tools and a vice. If you have it completely torn down, you may also consider a retrofit 'shoe' that increases the pump volume. The drip is not really a crisis, does yours have the grease cup? If yes, pack it and turn the cap down tight.

Just checked them
http://www.moyermarine.com/
go there and search 'water pump'

 

[Chris A.]

Just curious Loren, do you normally pull the shaft when you change the impeller? I thought that could disrupt the seals and create some leaking. I always pull the impeller carefully while leaving the shaft in place. The little c-clip pliers that you can get at the hardware store help make dealing with the retainer clip a bit more graceful...

Good luck on fixing the problem...

 

[Loren Beach]

Chris, I heard the same wisdom after we got this diesel inboard (and our first such engine configuration) back in the 90's. Local mechanics later told me to just be super careful/gentle and work the end of the shaft back into place. No problem with the oil seal, even now. The actual seal is a "lip seal" with a little spring around it inside the plastic/neopreme material.
I do remember reading that you would not want any burrs or a sharp edge to the shaft that you are guiding into the seal. Maybe that wisdom was right...

I wish I had a circlip remover -- tried one once and none of the pins were small enough for this particular little clip. Probably need to look around some more. It's a bugger to deal with even after the shaft is out.

Thanks again,
Loren

ps: here is the current pdf page from the pump maker. Good information. Interesting what you can find on-line.

 

[tenders]

My circlip remover came from Sears, off the shelf, and works great.

I seem to remember Moyer saying he didn't think the circlip is strictly necessary.

He has a new pump, slightly modified with better seals, knurled thumbwheels on the impeller cover for easy removal, and an o-ring instead of a paper gasket.

 

[Tom Metzger]

As I remember, I had to grind down the tips on my cir clip tool to fit the small clips.

And FWIW, I copied the name of:

Commercial Water Pump Rebuilders
1151 West 22nd Street
Houston Texas 77008
eMail: ushudsons@yahoo.com
Phone: 713 864 5199 Fax: 713 864 5190
http://www.waterpumpkit.com/home.html

I have no experience with them, but someone recommended them.

I bought my replacement pump at marineparts.com. They had the pump (Oberdorfer n202m-15)and a good price at the time.

 

[Loren Beach]

Ran the engine today and found that the water pump had not somehow magically healed itself overnight -- so I removed it and turned it over to my mechanic friend for a rebuild. This should be less expensive than a replacement. "More news as it happens" (as the talking heads always say on TV).
These pumps are $233.73 new from Fisheries Supply (out of Seattle) per their web site.

LB

 

[Rhynie]

Loren,
At least you can stay dry and tackle your problem. I tangled with a crab trap float last weekend (I know it did wrap up in there) and limped home thinking I had a line in my prop. I took a dive underneath yesterday and I'm missing 1/2 of one blade and about 1/3 of the other; it may have been brittle to start with. It looks like I'll be renting some scuba gear to swap it out this week sometime.
Ahhhh, the joys of boat ownership!

 

[Loren Beach]

"Oberdorfer!" (Bless you...)

Some Closure:
The old pump was deemed to be too badly worn inside the casting to be worth the labor to rebuild.
I was able to get a deal on a new one for about $200., sourced from Fisheries Supply in Seattle.
The new one uses an O-ring seal instead of the old paper gasket, too.

As further proof of how the old pump had lost pumping capacity, even with a new impeller, the new Oberdorfer primed in a heartbeat and a lot more water surged out of the exhaust.


LB