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Bruce In Bangkok Bruce In Bangkok is offline
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First recorded activity by BoatBanter: Dec 2008
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Default Dismanteling a Johnson F7B-903 impeller cooling pump

On Tue, 31 Mar 2009 11:12:51 -0700 (PDT), Len
wrote:

Hello ng,

I hate it when this happens: the impellerpump starts to leak salt
water on my engine and everywhere in my bilge.

On my Peugeot 60hp marinised diesel I have a Johnson F7B-903
impellerpump delivering seawater to the heat exchanger. The water- /
oil- simmerrings in this pump start to leak after a few hundred hours.
I had the pump revised/overhauled by a machine shop for good money
only 50 engine hours ago but now I have the same problem again.

I guess I am going to take the shaft out and polish it till it shines
before I put in new oil-simmerrings

Does anybody know if I can dismantle this pump without any
sophisticated tools like a hydraulic press or whatever?
Can I push the shaft out by hand or with a plastic hammer?

Thanks for your time... Any advice is highly appreciated...

Len.


The shaft will have to be pressed out of the bearings but (if I
remember correctly) it isn't difficult. But more to the point, there
is no reason for a pump to leak after a few hours of running. Most of
them don't leak after several years. Examine the shaft for wear and by
the way, parts are expensive.

I had a similar problem and discovered that the people that re-built
the pump simply installed new seals and the problem was the shaft
which had a groove worn in it where the seal was mounted. A new shaft
was a hundred dollars, or so, if I remember.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)