Yanmar 1GM10 Waterpump leaking

[ianwoods]

Help needed,
I have a 10 second drip from the centre of the body of the pump. No leak from the Speedseal cover or the pipes and clips. Seems to be small drain hole? in the middle of the body. Is this drip normal? Difficult to see a problem when I look at diagrams in the manual.
Many thanks for observations of what happens with your !GM10.
Ian Woods

 

[pete]

It will be the shaft seal there are 2 of them 1 to stop the water and 1 to stop the oil with a tell tail between. Easily changed and cheap from a bearing/seal factors but check that the shaft is not to worn.
Swap the new spring in the water seal for the old one as that will probably be stainless.
Also check the oil pipes below the pump for corrosion from the drip.
pete

 

[ianwoods]

Thanks for the info Pete,
Can I remove the pump without having to take off the bottom pulley? Access to my engine is only from above.

 

[Tranona]

Adding to what Pete says, not only check the oil pipe for corrosion, but also the front cover which is aluminium and the screws holding it on are mild steel. The screws holding the pump on are also mild steel. Not sure if you have to take the pulley off, but it does make access easy. My Yanmar dealer stripped my pump and replaced the seals for very little more than the cost of the seals.
BTW the hole is called a witness hole and is there to tell you when the seal is leaking!

 

[KenMcCulloch]

Hi Ian, I had this problem last year and changing the seals cured it. Be careful digging out the old seals as the pump body is bronze and vulnerable to gouging with a harder metal implement. You should be able to get the pump off without removing the pulley although it may be a bit awkward if you have limited access. You should also pay careful attention to the state of the shaft, if there's a pronounced groove in way of the seal you may find that replacing the seals is not a cure and you need to replace the shaft as well.

If you buy the seals from a Yanmar dealer they are about £12, otherwise as Pete says swap the springs as generic seals may not have s/s springs. (Actually you only need to do that on the water-side seal of course.)

Cheers

 

[NPMR]

I have a spare impellor housing/pump and find it easier to change the whole thing than an impellor. Then when the whole unit is on the bench/cockpit table, it is easy to deal with the stupid little screws holding the cover on the impellor.

It's quicker to change the pump thatn the impellor, I find.

 

[steve28]

Depending on how many hours the engine has done, i may be advisable to replace the bearings as well, the shaft tends to whip which causes sooner failure of the seals.

 

[ianwoods]

Thanks Ken for the detailed information.
Did you get the pump off without removing the bottom pulley and perhaps the belt?
Do I need to buy a gasket to between the pump body and the engine casing (or is it an O ring as on one of my diagrams)?
Did you use sealant to keep the gasket in place?
I certainly would appreciate learning of the finer details.

 

[ianwoods]

Thanks NPMR,
This sounds sensible.
How easy is it to get the pump off? You have to remove and reconnect two hoses and clips and perhaps hold a gasket in place? I am restricted in only having top access.
Advice please.

 

[KenMcCulloch]

[ QUOTE ]
Thanks Ken for the detailed information.
Did you get the pump off without removing the bottom pulley and perhaps the belt?
Do I need to buy a gasket to between the pump body and the engine casing (or is it an O ring as on one of my diagrams)?
Did you use sealant to keep the gasket in place?
I certainly would appreciate learning of the finer details.

[/ QUOTE ]
Yes the pump will come off without removing the pulley although if you are working from above taking the belt off might give you more spannering room. The pump fits in a hole with an O-ring which you can replace if you think it needs it. I use a smear of grease to stick the cover gasket in place when changing/inspecting the impellor but if you have a speedseal that obviously doesn't apply. I disagree about chnaging the whole pump; they are quite expensive, there are two hoses to fight with as well as 3 bolts although I agree about the ease with which the wee M4 bolts that hold the cover on can slip out of reach.

 

[fastjedi]

Agree. Take the whole pump off (no need to remove the pulley), take it home and rebuild carefully at home. More often than not you will need a new shaft too (circa £50)

This is a 1GM10 weakness, especially in sandy water (like the Solent). Under these circumstances they only last about 50 - 100 hours, although the rate of leak may not be immediately apparent if you don't have immaculate gel coat / perfectly dry bilges.

As discussed above, keep an eye on the two oil pipes below the pump. Many 1GM10's have deposited the contents of their sump into the bilges due to oil pipe corrosion. Mine had many coats of heat resistant paint (+ a breeze over with Yanmar grey) from new to help prevent this.

I guess yours could be difficult to inspect / refinish if access is from above. Don't ignore them!

 

[bendyone]

I replaced mine with rubber ones, cheaper and I think better than the yanmar ones

 

[ianwoods]

Hi Bendyone,
You have a good durable solution to decaying oil pipes. Would you be able to specify for me what you asked the pipemaker to make - spec of pipe; bore of pipe and size of hole in the banjo ends and of course the length of each from centre of each banjo hole? Many thanks for your guidance.

 

[ianwoods]

To all the generous respondents,
I am certainly appreciative of your solutions to my problem.
I will remove the pump with less trepidation and see to the seals and should the pipes be corroding, replace them with rubber ones.
Best wishes and many thanks to you all. Ian Woods.

 

[tangomoon]

SEnd it to Cellar Marine in Porthallow, Cornwall (Mr Skewes) ask him to refurbish INCLUDING new impeller (the dipstick didn't renew mine!) and it comes back nearly like new for £80ish

 

[bendyone]

I took the old ones into a hydrolic pipe place and they made the new one, about £40

 

[ShipsWoofy]

I don't know where you are, but I took my old manky rusty oil pipes to http://www.manflex.co.uk/ in warrington where he made up 4 new pipes in the shop while we chatted and passed the time of day. They cost a fair bit less than £40 in fact if I remember rightly I paid under £20 around 3 years ago. I only had to fit one set (twin engine) so have a spare for if, ahem, when the other engine goes.

For the pump, this may help a bit...

[ QUOTE ]
A common fault on yanmar 1GM10 engines is a dripping from the tell-tale hole on the water-pump. Left alone this will cause corrosion around the pump and will almost certainly corrode the oil pipes which are directly below the pump.

New seals for the pump will fix the problem and are a lot cheaper than buying new oil pipes. Though these can be manufactured from rubber hose by a hydraulic specialist, mine cost £9.00 for the two pipes. yanmar will remove £70+ from your wallet for genuine parts.

Left leaking for long enough, water might breach the oil seal. Sea water will not only destroy the pump bearings but could theoretically enter the engine. If your pump is dripping, <u>fix it now.</u>

I have recently repaired one of my pumps and photographed the method I used; this can be carried out by any competent diy’er. Tools required,

10mm spanner to remove pump.
7mm spanner to remove impeller cover.
Long nose pliers or proper tool to remove bearing retaining clip
11mm, 3/4in sockets and hammer to drift new seals.

Bearing grease
Sharp blade to remove gasket
Cleaning materials (wire or brass brushes)
Spray paint

128170-42120 Water pump seal (This is the one which has failed)
128170-42110 Water pump oil seal (You WILL damage this to get the other one out)
128170-42090 Water pump cover gasket (you may use gasket seal if you must!)


The first thing we must do is remove the retaining clip, careful with this I had to find it by a plant pot on my patio as it got away.

Now remove the impeller cover by removing the 3 retaining bolts. This allows you to remove and inspect the impeller and then gently drift the shaft and bearings out of the pump.

Here is the shaft and bearing races. When I removed this I found a small amount of melted rubber on the shaft which had come of the water seal and was the reason for the leak. I scraped off the rubber with a scalpel and used a little wet and dry to ensure the shaft was clean.

I can’t give chapter and verse on removing the old seals, it isn’t easy. Lots of tapping with screwdrivers and tugging with pliers is required. Do try not to damage the pump, it is bronze and there for not as strong as your screwdriver.

Fitting the new water seal with an 11mm socket as a drift.

Gently (gently means gently) drift the new seal home.

The water seal home and sealed.

The oil seal home and fitted.

The bearings were cleaned and re-greased. I used the ¾ socket to tap them home.

All openings and unpainted areas masked off for spraying

Finished and ready to go to the boat

EDIT>> I tried to find alternate parts (seals) from auto parts specialists and a well known marine hydraulic engineers in Warrington. After a day driving around I gave up and resorted to genuine parts.

I went to a place called Alec Martin Marine on the Wirral. Not only was he the only place holding stock, he was also the cheapest. A proper old fashioned marine engineers, do not be put off by the website. For most marine stuff, give them a call, he knows his stuff! They will mail order.

**usual disclaimers apply**

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