Yanmar 1GM10 Impeller

[John R Smith]

Folks

in the hope that someone else with a Yanmar 1GM10 diesel may be able to help. Last weekend I was trying to service my engine, and I thought I would check the water pump impeller (for which I had bought a spare impeller and gasket).

BUT the impeller cover seems to be held on with three tiny cross-head screws which seem to be corroded and won’t move. Am I trying to undo the right thing? Has anyone else encountered this problem?

I would have thought that the impeller ought to be easily removed for servicing . . .

John

[NormMessinger]

You are going about it correctly. Perhaps some "what-cha-call-it" (the stuff we call penetrating oil) will help. A little heat, not too hot to touch, will help the oil penetrate and it might take some hours to work. You don't want to twist the screws off but ya gotta get 'em out.

[martin schulz]

!!!

...you yhould have asked me when you had the chance John. I also have that engine inside my boat, although I bet she weights probably twice as much as your's.

But Norm is right try some sort of agressive oil first.

[John B]

they are usually a generic pump... johnson..?. anyway, the problem often occurs. you may have to take the whole pump off... usually just a couple of bolts and the hoses of course. I recall having to drill one out and re tap for a bigger thread.Once you've done that,you go to some extra trouble to make sure the new ones are well greased and with fresh slots so there isn't a problem next time.
you can also buy some bolts with extra large knurled heads on them so you can undo them by hand . thats always struck me as a good idea.

[Ian G Wright]

It will be a Jabsco pump I think, you might get some help from http://www.jabscoshop.co.uk/ but in the mean time just keep trying, no left hand threads or tricky bits,,,,,,, those thumb screw replacments are a good idea as is a couple of spare impellers.

IanW

[John R Smith]

Thank you all for your replies. Martin, I hadn't tried taking it apart when we met up, this was Sunday last.

I must say, that for a component which you might need to access in a hurry, possibly at night in a rough sea, I have never seen such a stupid arrangement. Even if you can get the fiddly little screws out, aren't you just bound to drop one of them in the bilge?

Come back Kelvin, all is forgiven ;)

John

[Andrew Craig-Bennett]

The thumb screw replacement that Ian is praising is called a Speedseal; it costs about forty quid and is a really good investment.

You think you've got trouble - I'm the man that can show you trouble - the water pump on a Volvo MD2 is at the back of the engine, which in my case means under the floor of the watertight cockpit, requiring the enthusiast to lean across the engine, and it has six fiddly little screws to drop in the bilge. At least, mine did have, until this winter, when, noticing that three of them were doing nothing as the threads had gone in the casting and the pump was leaking round the shaft gland, I paid a local engineer to remove it, machine the shaft, drill out the holes, tap them and fit six stainless bolts, which should keep the show on the road for a little longer...