Yanmar 1GM10 : leaking impeller

ERICH

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Hi everyone , this is my first post so please be gentle !

I have an 1GM10 on my Hunter 27OOD and there is water dripping from/around the bottom bolt of the three holding the impeller housing onto the crankcase ( not from the impeller gasket )
there are two "open " holes ( top and bottom) in the " waisted " part of the housing behind the actual impeller and wonder what they do and whether the water is coming from the bottom hole but it is very difficult to see the actual leak!

Has anyone come across this problem before and what is the fix ?

Thanks
 
I think you may have a very common problem with this engine.

I am not an expert, but until recently I owned a 1GM10. Look straight away at the oil pipes below the pump. If they are corroded from the leak, replace them straight away - otherwise you will lose the oil from the engine one day when it is running, which can be a bit expensive.

The two holes are, I think, to allow water to drain clear when the water side shaft seal has failed, in order to prevent water entering the engine luboil through the oil side seal.

I think you need a new pump shaft and seals and it may be easiest to buy a new pump.

Do check those oil pipes!
 
Re: Yanmar 1GM10 : leaking impeller

Mirelle's diagnosis sounds very familiar having just completed replacement of front oil pipes, water pump seal and shaft on my 1GM10. The front oil pipes in question were around £100 for the two so I would get it sorted pronto before they begin to rust. I used French Marine for my spares and were very helpful. (Tel: + 44 (0) 1206 302133 or 305233)

As an aside you can buy a complete workshop manual on CD from ebay from http://stores.ebay.co.uk/Marine-CD-Manuals for £3.99 which is very useful if you haven't already got one.
 
Yep.
If you take off the pump unit (pretty straughtforward), and either dismantle or take to someone, you will either need new seals, or new seals and a new shaft (big chance of this).

Ditto oil pipes. Pain. Expensive. Somebody in an earlier thread recommended a flexible pipe of some form. Do a search if this is of interest.
 
Totally argree with the other awnsers, I had some rubber pipe made to suit, see the picture below. I had an extra tube put on the one to help protect it.

oil.jpg
 
As per the other replies.
There are two seals - one water seal to keep the water in the side nearest the impellor and one oil seal nearest the engine to keep the oil in the engine. When the water seal starts to leak (usually due to grit etc in the sea water) the drips are seen from the small hole between the two. (As the others say - it drips onto the oil pipes causing corrosion). Easy to replace pipes and they're not too expensive - just coat with hammerite for future longevity).
Anyway - back to seal replacement. Whole pump removes from engine - don't worry, it's above the oil level so you won't lose engine oil.

After taking off cover and removing impellor - you will find that the bearings/shaft are held in at the other end with a circlip.

Once circlip removed they'll slide out. The seals look the same but are actually slightly different sizes. The oil one is probably ok but will be damaged (most likely) when you remove it to get to the water seal. So you'll have to replace both.

New seals, new shaft if the old one is worn in any way - and it'll all slot back together. IF you don't do the job soon the shaft will wear even more due to salty water wearing it out - and the shaft is the very expensive bit! (Probably about £8 for each seal but more like £70 for the shaft).

Any more questions just ask.

By the way - there is a correct way round for the seals - flat sides towards the air gap in the middle. Spring/concave sides towards the oil or water.
 
Re: Yanmar 1GM10 : leaking impeller

You will need a new water pump shaft. Almost certainly . It will cost £75+ . They last about 500 engine hours for me.
It is possible to remove the groove corresponding to the water seal with emery paper but it will not last. It is possible to get water pump shafts sleeved for less than £75 where a thin stainless tube is fitted to the shaft to cover the groove.

I always end up in Marine Power getting the new shaft , as I would rather be using the boat than waiting for the work to be done.
 
Re: Yanmar 1GM10 : leaking impeller

flat sides towards the air gap in the middle. Spring/concave sides towards the oil or water.


I had a similar prob on my engine 5.7dp,and replaced the seal £3.65 from keyparts,on taking the old seal out the spring was facing the impellor,and to my mind it should have been the other way round is there any reason why this should be
 
I put a second hose on top of the one from the raw water intake cock to the water pump on my Yanmar for the same reason of protection against rubbing. It works great.
 
Check the bearings, when the seals go its logical to check those as well, also the original shafts have been hardened so they last longer with the seals. I found this out after my "Made" shaft lasted only two years, the grooves it had were quite deep and that was 316 stainless.

Steve
 
service kit

I had exactly the same problem as you describe with my Volvo 2002 water pump.
I took advice of this forum and bought the service kit (about £50 from Keypart) this includes a new shaft, bearings seals and new cover.
It took about an hour to carry out the whole service onboard the boat.
Only special tool I had appart from ring spanners and socket set was a pair of circlip pliers.
I now have a reconditioned pump, as good as new.
 
IGM10 Oil Pipes

Where did you get the pipes made up and at what cost? I need a pair for my 1gm10...thanks

Ditto for me - my pipes are also corroding and pump needs servicing - I had thought about getting some stainless pipes made somewhere (if possible) but rubber seems like just the ticket - Could you PM me with details?

Many Thanks


JuSw
 
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