Leaking raw water pump

[HighTide9000]

Hi everyone,

I recently changed my raw water impeller and following that I noticed a slow drip (1 small drip every 2 mins) coming from being the impeller manifold. The face of the impeller manifold is fine, the gasket is doing its job and all is well sealed there. This drip is specifically coming from behind the manifold. Any advice on how I might be able to repair this without breaking the bank?

Thanks in advance!

[Bill O]

The pump most likely needs a minor/major kit to rebuild for the back seal/bearings.

If you don't want to do the rebuild work, look into the price of a new pump.

[mike d.]

I have a Volvo Penta , and had the same problem ! I just got a seal, and impeller rebuild kit for about $70 bucks if I remember right ! That was in in 2006 !

[Wotname]

Bill O is correct, the pump will be leaking from the shaft seal and this seal needs replacing. The shaft itself may need remedial work or replacing. The bearing should be replaced as a matter of course.

Be aware that parts can vary greatly in price depending where you buy them.

For instance, I recently rebuilt a largish water pump">raw water pump (off a 100 hp Ford Lehmann). New pump was around $2000, parts from the main Jabsco marine supplier were around $800 while parts from the local industrial pump shop were around $250.

Parts for another smaller Yanmar pump were around $120 from the Yanmar agent yet only around $20 from a seal and bearing supplier.

Shop carefully.

[SV__Grace]

You'll notice a hole or slot in the body of the pump and when water leaks through it you need to renew the seals in the pump.

Doing so is easy enough once you get the kit, or you can order a new pump and they are easy to swap out, or what I did is order a new pump for immediate fix and rebuilt the leaky pump for a spare.

[johnrseager]

I agree with others - this is a leak from the shaft seal. I have just rebuilt the raw water pump on my Yanmar 3GM30 - it is an easy enough job. The shaft seal cost ZAR190 (US$13) and the bearings, of which there are two, were ZAR162.80 each (US$11), from my local Yanmar agent (Cape Town). They would be even cheaper from the local bearing and seals agents but I was told by one 'expert' that they may be unusual sizes and therefore chose to buy what I was sure would fit. Buying a new pump when repair is relatively quick and easy seems like an unnecessary expense. Of course, if the shaft is badly scored things may be more difficult but I would try the cheap repair first.

[AndyinAbudhabi]

I would fix it sooner rather than later. Had a leaking raw water pump on the generator and ended up with salt water inside the engine. Didn't notice it for a while and when I did it had made a real mess. An expensive learning curve!

[Djarraluda]

There was a thread on this a few years ago. 2 tricks I learnt reading that, to ease the fix. Once the impeller is removed:
1: It could just be the spring that wraps around the shaft seal behind the impeller. This may be able to be replaced by an O ring as a fix.
2: The old seal can be pushed out of a lot of pumps, using hooked "pick". Reach through those drain holes at the back (if you can) and simply push the seal out. Source new seal and replace.
Roger

[Uncle Bob]

Originally Posted by Djarraluda

There was a thread on this a few years ago. 2 tricks I learnt reading that, to ease the fix. Once the impeller is removed:
1: It could just be the spring that wraps around the shaft seal behind the impeller. This may be able to be replaced by an O ring as a fix.
2: The old seal can be pushed out of a lot of pumps, using hooked "pick". Reach through those drain holes at the back (if you can) and simply push the seal out. Source new seal and replace.
Roger

Ditto. Recently did my pump, bearings were perfect, seal spring was mostly rust, replacement seal with "o ring" was sourced from a bearing and seal vendor, I got two for A$10.00, now I have the spare I know that I will never need it.

[Djarraluda]

Originally Posted by Uncle Bob

Ditto. Recently did my pump, bearings were perfect, seal spring was mostly rust, replacement seal with "o ring" was sourced from a bearing and seal vendor, I got two for A$10.00, now I have the spare I know that I will never need it.

More likely, in a couple of years time you will find another use for that same O ring. Within 3 months you will need it for the water pump again.

[Boatyarddog]

Which pump?
That would help.
Sv Cloud Duster

[stormalong]

Originally Posted by Djarraluda

There was a thread on this a few years ago. 2 tricks I learnt reading that, to ease the fix. Once the impeller is removed:
1: It could just be the spring that wraps around the shaft seal behind the impeller. This may be able to be replaced by an O ring as a fix.
2: The old seal can be pushed out of a lot of pumps, using hooked "pick". Reach through those drain holes at the back (if you can) and simply push the seal out. Source new seal and replace.
Roger

Why would you demount the water pump, replace the spring in a pump seal, not knowing if you have fixed the problem and put it back in to save the few dollars that a new seal would cost?

Even if it works the seal is probably very worn and you will have to repeat the process soon to put in a new seal.

[Al B]

Volvo Penta raw water pump failure on starboard engine while on a 2 day cruise
circulation was enough too not effect temp reading ,
I discovered that evening when gasing up , opening hatch too check oil ,
White salt was all over entire engine , Serpentine belt thru salt water all over Going on hours , having no indication
Of coarse no spare , locally the few marine shops had no volvo parts , Everything available but on line , Returned on other engine ,
cleaned engine , following weeks one item failure after another
air flow sensor - electonic coil pak - alternator - starter - ECM was wet and loaded with salt , Very costly item , but seems ok , fires up

[Catboat Willy]

If you could tell us the manufacturer of the pump, we could give you more specific information as to how to repair it and where to get the lowest priced parts.
de.....w2cwl

[jamhass]

As a slight addition to the discussion (this is all implied in the above, I just want to make the recommendations from above explicit):

When sourcing replacement non-OEM seals, it is important to source ones either with SS lip springs or o-rings. If you can't find ones with SS springs, you can replace the springs with o-rings. They last just fine.