Yanmar 1GM10 - leaky parts. Advice?

Tim Good

Tim Good

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Ok I'm not a hugely up on Diesel engines but I'm learning.

Replaced my impeller last year with a new gasket but its still a bit leaky. I don't want to over tighten the bolts so has anyone got any other advice on make a decent seal?

As you'll see on the photo housing behind the impeller is also leaky. Do I need to remove and replace gaskets this or can I seal it in place?

It does appear to be dripping and corroding the pipe below which doesn't look like an especially good idea. Unsure what that pipe is but I know I don't want it to corrode through. Should have been stainless or a flexy pipe really considering where it is.

View attachment 31246
 
Take the pump off, strip it down and replace the seals and bearings. If the shaft is damaged you'll have to replace that as well, or put a sleeve on it (if you can get one the right size), or buy a complete new pump. Bearings sleeves and seals available from www.bearingboys.co.uk
You also need to replace the oil pipe, either with an expensive Yanmar part or by finding a local hydraulic hose company that will make up a replacement (possibly with flexible hydraulic hose - don't know as I've never had to replace one myself).
 
As above and it looks like the hose clips may have been leaking as well. These are an easy pump to strip down and the seals were available from my local bearing supplier (but do check the spindle for ridges). This link to an exploded diagram may help.
http://www.google.co.uk/url?sa=i&rc...m0Cc3ay3MH66M6ZHX4uXqhug&ust=1367311259583754

Depending how badly rusted the oil pipe is you may be able to clean it up and repaint it, I always kept mine lightly greased up, also keep an eye on the tell tail hole in the pump body from time to time.
Pete
 
That looks like leaky hoses rather than the face plate. That whole area is a cocktail of metals - aluminium housing, bronze pump and mild steel screws. Looks exactly like mine did. As suggested, take the pump off and overhaul. Replace all the steel screws, including the ones holding the cover on as they will also be corroded. You may get away with just cleaning up the front cover and painting - big job to remove and do any more cleaning up. Replace the oil feed tube with a flexible one made up by a local hydraulic shop - take the old one in for a pattern. Replace the face plate of the pump with a Speedseal cover to get a better seal and make changing impellers easier. Take all the hoses off while you are at it and clean them through, including the entry port into the cylinder.
 
A smear of silicone sealant when attaching rubber pipes will eliminate any leak there. You should be able to tell if the leak is the front or back - if back then it is internal seals/shaft, if front then pipes or cover. The cover eventually wears so check for grooves.

The metal pipe below is an oil pipe, and commonly has to be replaced (££££!) when the pump leaks. If it looks dodgy, don't wait for it to fail - replace it.
 
Pye_End said:
If it looks dodgy, don't wait for it to fail - replace it.
Click to expand...
Just enlarged the photo and it looks fairly corroded at the bend just under the clip.
Agree with the Speedseal comment, I've had two Yanmars so far and fitted Speedseals to both.
Also forgot to mention - get a small bronze wire brush and clean off all the bubbling paint and corrosion before you start (so you don't end up with muck and rubbish where you shouldn't), then do the dismantling. You can then paint the corroded engine casting behind the pump with some etch primer.

Also (!) it's worth taking off the flexible outlet hose from the pump to clean it - they seem to attract a lining of something or other that sticks to the pipe wall.
 
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These kits are very convenient but not the cheapest way to source generic parts such as seals and bearings. I would advise stripping the pump and deciding what you need first, if the shaft is not badly scored you may not need to replace it. You will probably find that the outer (water) seal on the shaft is worn, this happens because particles of sediment in the cooling water work their way under the seal and gradually start to wear the seal and (more slowly) the shaft. If the inner (oil) seal is intact you will probably find that the bearings are OK. Like most 1GM10 owners I had exactly this problem on a boat I used to own and I found that replacing the seals was all that was needed, although as other posters have already said it rather looks as though the top hose connection may be leaking too.

If you are not going for a speedseal make sure you have a supply of spare faceplate gaskets, and you may also want to consider a useful modification; cut three short lengths of studding and screw them into the wee bolt holes in the pump body, and the faceplate can then be secured with knurled thumb-nuts. Doing that makes fitting the gasket and faceplate back on loads easier (note that there are 6 possible orientations for the gasket, only one of which is correct). If you ever have to change the impeller at sea you will thank me ;-).

Hope that helps.
 
KenMcCulloch said:
cut three short lengths of studding and screw them into the wee bolt holes in the pump body, and the faceplate can then be secured with knurled thumb-nuts. Doing that makes fitting the gasket and faceplate back on loads easier
Click to expand...

There is a great idea.

My only issue with stripping down to see what I need is that I'm on a swing mooring and moving the boat to the marina for a weekend of work. If for some reason I can't put it back together then getting to the mooring under sail single handed might be tricky. I think I'll get the seals and see from there.
 
P.S. The pipe that rusts below the pump is a key part of the lubrication system, an oil pipe, so if it corrodes through your leaky waterpump will become a more minor problem. Quite a lot of people replace these pipes by getting a hydraulic hose shop to make up a flexible (and therefore non-rusting) hose to the correct length, also about 1/4 the price of new steel pipes from the Yanmar shop.

Cheers
 
Agree you may not need to replace the shaft which is the most expensive part. Dismantle it first and buy what you need. my local Yanmar dealer replaced the seals for me for 1/2 hour labour if you don't fancy doing it yourself. You may also find the fastenings though the front cover holding the pump onto the block are corroded. The threads will be OK but the heads corrode. You obviously don't need the face gasket if you are going the Speedseal route, nor the impeller if you have just fitted a new one, unless you want a spare.
 
Tranona said:
You may also find the fastenings though the front cover holding the pump onto the block are corroded. T
Click to expand...

And what is the option then? Tap them out slightly larger? Doesn't seem like much room to re tap the holes if they are gone.

srp said:
Teither with an expensive Yanmar part or by finding a local hydraulic hose company that will make up a replacement
Click to expand...

Hercules Hydraulics said they'd make one up for me with their eyes closed but need the original pipe or the exact spec of the fittings on either side. Since I have limited time over a weekend to take it off, take it down there and get it made, I wondered if anyone knows the exact size / dimensions / length of the fittings so that I can get it made up no and then collect as I drive to the boat?
 
northcave said:
And what is the option then? Tap them out slightly larger? Doesn't seem like much room to re tap the holes if they are gone.



Hercules Hydraulics said they'd make one up for me with their eyes closed but need the original pipe or the exact spec of the fittings on either side. Since I have limited time over a weekend to take it off, take it down there and get it made, I wondered if anyone knows the exact size / dimensions / length of the fittings so that I can get it made up no and then collect as I drive to the boat?
Click to expand...

It is not the threads, but the heads which corrode. This sometimes means that the heads round off as soon as you put a spanner on them. So take them out carefully and replace if the heads are damaged.

Sorry can't help on the hose sizes.
 
+1 more on replacing the oil pipe. If it fails you will find out if the oil pressure warning works. If you switch the engine off immediately you will not ruin it but of course you may well get into some serious trouble without it! At best you will have a litre of dirty engine oil in your bilge. I replaced two before we realised it was the water pump leaking that was the cause of the problem.
 
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