# Raw Water pump leak



## fmueller (Mar 14, 2012)

After replacing my raw water pump impeller before launch this spring I noticed we have a slow drip from the pump when it is running. I thought it was the pump cover gasket but have now discovered that it is leaking through the shafts water seal and out the air gap.

I saw compass marines excellent write up about rebuilding a pump, and ours is identical to his. It doesnt seem like too bad a project, but I would strongly prefer to wait til next winter to do it (our sailing season is short enough as it is and I want to spend it sailing not working on a pump). Is that foolish? Will the leak do any additional damage? Is it likely to get worse? 

We really only use the motor to get in and out of the slip and so maybe 40 hours a year, and we leave the raw water intake closed whenever not motoring. The leak is more than a drip, but less than a torrent...maybe a quarter cup a minute or less.

The motor is a westerbeke 20Btwo.

I appreciate your thoughts.

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## svHyLyte (Nov 13, 2008)

fmueller said:


> After replacing my raw water pump impeller before launch this spring I noticed we have a slow drip from the pump when it is running. I thought it was the pump cover gasket but have now discovered that it is leaking through the shafts water seal and out the air gap.
> 
> I saw compass marines excellent write up about rebuilding a pump, and ours is identical to his. It doesnt seem like too bad a project, but I would strongly prefer to wait til next winter to do it (our sailing season is short enough as it is and I want to spend it sailing not working on a pump). Is that foolish? Will the leak do any additional damage? Is it likely to get worse?
> 
> ...


Behind the impeller is a bearing plate under which is a lip seal that the impeller shaft passes through. The lip seal is intended to prevent raw water escaping from the impeller housing, where it is pressurized by the deflection of the impeller vanes over the cam lobe, and reaching the shaft bearings and, if the oil seal in the engine is weakened, potentially the interior of the engine itself. The weep hole in the pump is there to warn you when/if the impeller lip seal is leaking and prevent water collecting in the shaft gallery. Ignore the leak at your own peril. The inconvenience of replacing a lip seal is nothing compared to the inconvenience of replacing the pump itself and, potentially having to repair the damage that may be done to your engine. Your call...


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## fmueller (Mar 14, 2012)

Can I replace the lip seal without removing the pump from the engine or does this require a complete pump rebuild(bearings and oil seal too)?


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## desert rat (Feb 14, 2013)

He wants a shade tree, bubble gum and bailing wire fix good for one season.
'IF' the lip seal is the only thing worn out maybe but if not oh ****. I only know land vehicles and a water pump is a water pump but everything wears out I wouldn't take the chance.


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## svHyLyte (Nov 13, 2008)

fmueller said:


> Can I replace the lip seal without removing the pump from the engine or does this require a complete pump rebuild(bearings and oil seal too)?
> 
> Sent from my XT1060 using Tapatalk


It depends upon how readily you can reach the inner bearing plate and existing lip seal and how dexterous you are. I have been able to do it in a few cases but failed in others. Even if you must remove the entire pump, however, it isn't that difficult, just a bit tedious but not bad, really. Just a pain in the neck.


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## MarkSF (Feb 21, 2011)

Sorry but once you get any drip, you shouldn't be using that pump - for two reasons - one, you could get salt water in the engine. Two, the salt water is destroying the internals of the pump and making it more and more likely that you can't rebuild it.

The quick fix is to buy a new pump, and then rebuild the one you have for a spare. Having a spare means your cruising plans can't get ruined by a leaking pump. I went to the lengths of installing an extra set of bronze hose adapters in my spare pump, for a quick emergency swap out if it is ever necessary. Swapping the pump is quicker than changing the impeller, or messing about with seals.

Any idea what make and model of pump you have?

I just replaced my Sherwood, which has a very short life due to poor design, with an Oberdorfer.


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## JimsCAL (May 23, 2007)

A quarter cup a minute is a pretty bad leak. It needs to be attended to. I wouldn't try to wait until the winter to fix it. MarkSFs suggestion of getting new pump and then rebuilding the old one as a spare is good one. You may not like the cost of a new pump however - I would guess over $500 if you get from a Westerbeke dealer.


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## jkimberly (Jun 18, 2008)

Just a quick thought . . . Setting aside any leakage INTO the engine, you have to contend with that salt water affecting associated engine parts outside the engine. I went through pretty much the same problem only with a 1gm10 yanmar. Directly under the dripping pump are two oil lines, the cost of replacing these two lines was equal to or better than the cost of a new yanmar water pump.

Initially I went the rebuild route, twice, but apparently the pump was too far gone as it started leaking again half way through the season both times. 

John


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## eherlihy (Jan 2, 2007)

I've been down this road, and you can read ALL about it here; http://www.sailnet.com/forums/diesel/60992-rebuilding-oberdorfer-pump.html. The cliff notes version is that it is far more cost and time effective to buy a new pump at Depco Pumps in Clearwater, FL.

By waiting you risk spraying seawater over your engine casing, oil pan, and motor mounts. This will lead to corrosion. You also risk possibly contaminating your engine oil with seawater, which will lead to other problems...

The free advice that I offer is to spend the $300, and buy a new pump, NOW.


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## night0wl (Mar 20, 2006)

Its around $200 for a new pump...you'll spend much more time than that fixing this part...


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## Stu Jackson (Jul 28, 2001)

eh is completely right.

Depco Pump Company is a good source. If you have a Sherwood, replace it with an Oberdorfer.



eherlihy said:


> I've been down this road, and you can read ALL about it here; http://www.sailnet.com/forums/diesel/60992-rebuilding-oberdorfer-pump.html. The cliff notes version is that it is far more cost and time effective to buy a new pump at Depco Pumps in Clearwater, FL.
> 
> By waiting you risk spraying seawater over your engine casing, oil pan, and motor mounts. This will lead to corrosion. You also risk possibly contaminating your engine oil with seawater, which will lead to other problems...
> 
> The free advice that I offer is to spend the $300, and buy a new pump, NOW.


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## eherlihy (Jan 2, 2007)

night0wl said:


> Its around $200 for a new pump...you'll spend much more time than that fixing this part...


the ~$300 factored in tax, shipping, and (for after the install) beer.


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## night0wl (Mar 20, 2006)

eherlihy said:


> the ~$300 factored in tax, shipping, and (for after the install) beer.


Still money well spent....keep the old one as a backup for parts.


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## Dave_E (Aug 7, 2013)

Drop $200, get a new pump, R&R in less than an hour (that's if you take a nap) and be happy. All that salt water is going to make something look "real nasty" in no time.


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## JimsCAL (May 23, 2007)

Here's the parts listing for the 20BTwo pump on Marine Diesels Direct.
http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&page_ident=37115-0&model=20B TWO / 30B THREE&manufacturer=Westerbeke&title=Sea Water Pump - Johnson - Replacement Only (48080)&quant_position=&catalog=37115&printparts=&printservice=&printoperators=&comment1=

As I predicted, dealer price for new pump is north of $500.


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## fmueller (Mar 14, 2012)

Is there a reasonable source for less expensive alternatives? Or does anyone sell remanufactured pumps?

I don't mind doing the rebuild if need be bit hate to do it during the sailing season.

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## eherlihy (Jan 2, 2007)

See the Depco Marine Pump catalog, page 139... then call them to verify and get a price. I would be surprised if it is $500


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## MarkSF (Feb 21, 2011)

I wonder if there is an Oberdorfer that will fit. They tend to go for about $250. Maybe ask on a forum specific to your boat model, if anyone has done it.

I found a reference to replacing my Sherwood with the Oberdorfer 202, on a Catalina forum.


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## christian.hess (Sep 18, 2013)

pumps are interchangeable for sure...just try to get the right parts numbers


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## fmueller (Mar 14, 2012)

Is there a forum specific to 49 year old French boats? Probably not. In any case this boat was repowered so the motor isn't original. The water pump is westerbeke 033636, which I understand has been replaced by 048080. 

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## JimsCAL (May 23, 2007)

Your choices seem to be the following:
1. Get a price on an new pump from Depco. Hopefully its less than Marine Diesel Direct. 
2. Buy a rebuild kit and rebuild it yourself.
3. Have a shop rebuild the pump for you. I had my local Yanmar dealer do this when I had the same problem and didn't have the time to do it myself. Cost was about half that of a new pump.

The reason you don't want to let this go is that with an engine mounted pump like that, there is the possibility that water will get past the inner seal and you'll have water in the engine oil. You'll then have a much bigger problem than a bit of water to pump out of the bilge.


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## fmueller (Mar 14, 2012)

Thanks for all the advice.

Sounds like doing nothing is a bad idea.

A new pump from Depco is $470.
The rebuild kit is $191.

as much as I prefer not to, I think I'll be going the rebuild route. I'll let you know how I make out...hopefully without too much drama.

~Fortunat


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## christian.hess (Sep 18, 2013)

well is there a way you can measure the shaft and other tolreances BEFORE buying the rebuild kit

the more you know the better you will be in the end

I searched yesterday and found those same prices on diesel direct and other parts places

basically 200 for a rebuild kit and almost 500 for a new pump


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## Capt Len (Oct 9, 2011)

Many pumps have a ceramic shaft .seal, Pretty fragile and needs special care installing.


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## Minnewaska (Feb 21, 2010)

I find rebuilt raw water pumps to be fairly unreliable or have much more limited lifespans compared to new. Personally, I believe the economics of new make sense here. 

Although, I acknowledge they are more expensive than I can understand. They are a simple pump, with no motor. Rebuilt pumps should be vacuum packed and kept as emergency spares.


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## sailhog (Dec 11, 2006)

I have rebuilt an oberdorfer a couple of times, and if I can do it, you can definitely do it. Rebuild kits come with instructions... I think it took about 1.5 hours after the pump was off. The only thing that was a little unclear to me had to do with the lip seal. It needs to go on facing in the correct direction. If you have any questions, go online and ask. 

Good luck!


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## christian.hess (Sep 18, 2013)

yup some parts are unconscionable price wise...its part of the reason many people hat diesel inboards...some are priced correctly some just want to slap you in the face

volvo penta anyone? even yanmar 

anywhoo

back to pumps

some rebuilds are worth it some not...thats why its good to find out your current tolerances especially for the shaft seals and where they go..bearings if used...etc...and compare to new...


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## L124C (Oct 4, 2007)

svHyLyte said:


> Behind the impeller is a bearing plate under which is a lip seal that the impeller shaft passes through. The lip seal is intended to prevent raw water escaping from the impeller housing, where it is pressurized by the deflection of the impeller vanes over the cam lobe, and reaching the shaft bearings and, if the oil seal in the engine is weakened, potentially the interior of the engine itself. The weep hole in the pump is there to warn you when/if the impeller lip seal is leaking and prevent water collecting in the shaft gallery. Ignore the leak at your own peril. The inconvenience of replacing a lip seal is nothing compared to the inconvenience of replacing the pump itself and, potentially having to repair the damage that may be done to your engine. Your call...


And with that....ENJOY YOUR SAILING SEASON!:laugher


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