Water Pump

tdw · #1 (**permalink**) 05-20-2007

Engine is a Bukh24, three cylinder. Diesel of course. Salt water cooled.

A few months back we caught the dreaded plastic bag in the intake, result being fried water pump impellor. Today , however , I noticed that we have an oil leak coming from the water pump housing itself, ie not the impellor housing but the main pump assembly.

Before I either rip the thing off and re build it or have it rebuilt does anyone have any thoughts ?

Simplest answer I can come up with is that when the water pump overheated it has also taken out the gasket sealing the main pump from the impellor housing but any thoughts, comments, suggestions ect , gratefully received.

Other than changing the impellor I've never pulled a water pump to bits, if it's just a gasket then even a moron like me can fix that but I'd like to be prepared in case it could be something else.

Idiens · #2 (**permalink**) 05-20-2007

Dunno the Bukh pump, but on a Volvo I would agree with your diagnosis. There are two lip seals on the Volvo I know, one facing the impellor and one the engine oil. Other than needing care to remove the old and replace the new, without damaging the housing, it's not a difficult job.
Worse is when the bearings are worn out - they need a lathe to turn the old ones out and thermal assistance to get the new ones in.

bestfriend · #3 (**permalink**) 05-20-2007

Wombat - Are there weep holes in your pump? If it has holes and leaks from there, it is the seals. Pinpoint the leak, clean off the pump, run the engine, and watch for the leak. If it leaks from the gasket between the block and pump, no big deal. The rear seal could also be blown, but its harder to tell because of the location close to the block. If you replace the rear gasket and it turns out to be an inner seal, it will find a way to leak again. If the leak comes from the front, where it connects to the impeller housing, it is the pump seals. Engine oil coming all the way from the block out the front, you either need to rebuild or install a new one. I don't trust rebuilds. I installed a new one and rebuilt the old one for a spare. If you take the pump off, check the shaft for tightness in the bearings.
So, first locate the leak, if its from the rear mount replace the gasket first. If it is from the front, you have a blown seal and there is oil where it should not be, so rebuild or replace. For a rebuild, hire a pro, peace of mind.

Also, check this site for info:
Torresen Marine's Marine Diesel Direct :: Index The Sailboat Specialists
Best

tdw · #4 (**permalink**) 05-20-2007

Hmm....thanks to you both for the advice.

I am not the most mechanically minded individual you will ever meet but I would like to know that I can repair small/medium problems in the engine if only because of a need to be self sufficient.

Have a very good mechanic on hand, so will probably get some advice from him (when the bugger comes back from his latest cruise) and then see how much I can do myself.

The pump is not noisy so I'm thinking just gaskets but the yard owner did comment on the small flow of water coming out of the exhaust last time we slipped. On the other hand the engine has absolutely no over heating problems. Yes I spotted the blockage fairly early on, the exhaust note is a dead giveaway, but we did not overheat the engine itself.

The oil leak itself seems to be coming only from the seal that is between the main pump and the impellor housing. It's not a huge amount that's come out, a thimble full or two is about all. Made absolutely no visual difference in the sump level.

If the thing does need a rebuild then I'll probably put on a new one but will rebuild the old for a spare and to get the experience.

Thanks again.

ps - pump is on the front of the engine block. Working from impellor back it is the first seal but if it leaking then there will be some oil undoubtedly getting into the impellor housing and therefore coming out the exhaust which is not good.

tdw · #5 (**permalink**) 05-20-2007

ps -

BF, I don't know what a weep hole is, to be honest but I don't see any evidence of something that could be one.

jmunson2 · #6 (**permalink**) 05-20-2007

On our Perkins, the mechanic stated the water pump was leaking some oil, indicative of needing a new pump.

Depending upon the age of your pump, I'd strongly consider replacing it. I believe the job is fairly straight forward, just R&R. Check with your mechanic to be sure.

Sincerely,

/s/ Jon C. Munson II

tdw · #7 (**permalink**) 05-20-2007

Quote:

Originally Posted by jmunson2

On our Perkins, the mechanic stated the water pump was leaking some oil, indicative of needing a new pump.

Depending upon the age of your pump, I'd strongly consider replacing it. I believe the job is fairly straight forward, just R&R. Check with your mechanic to be sure.

Sincerely,

/s/ Jon C. Munson II

Given the importance of the damn things replacement is on the cards. I'm hoping that I can pay mechanic for advice but do the work myself.

bestfriend · #8 (**permalink**) 05-21-2007

Sounds like you need a new pump. My biggest piece of advice, if you are going to do it yourself, is to take pictures of the set up before you dismantle so you get it all back together properly. That comes from learning the hard way.

tdw · #9 (**permalink**) 05-21-2007

Quote:

Originally Posted by bestfriend

Sounds like you need a new pump. My biggest piece of advice, if you are going to do it yourself, is to take pictures of the set up before you dismantle so you get it all back together properly. That comes from learning the hard way.

That dear sir, is about as good a piece of advice as I've ever received.

Things are looking good though. Mechanic is more than happy to guide me through the process but I'll do the work myself. Who needs skin on their knuckles anyway.