Yanmar Water Pump Seal

[richardabeattie]

It seems my 2GM20 raw water pump failed because I had not changed the rubber seal often enough - the seal which is visible when the impeller is removed. But I've now been told that the seal should be changed every year. Is that right?

 

[sailorman]

It seems my 2GM20 raw water pump failed because I had not changed the rubber seal often enough - the seal which is visible when the impeller is removed. But I've now been told that the seal should be changed every year. Is that right?

Not on my Nanni it isnt @ replaced each 100 hrs ( ie PA ).,
buy replacements from a factor, bearing boys or similar

 

[vyv_cox]

I have changed mine once, when it failed, in well over 10 years since I fitted the engine new.

The seal fitted to a Yanmar has a spring made from a copper alloy, which corrodes and crumbles away. There is an equivalent Volvo one, otherwise identical, that has a stainless spring that lasts better. Marine Power stock one with a stainless spring that they will sell you at a far more sensible price than either of these.

 

[rudolph_hart]

I have changed mine once, when it failed, in well over 10 years since I fitted the engine new.

The one on my 3GM30F leaked after 16 years, but only because I overtensioned the drive belt this year (they really are rubbish, these smilies!). Simple job to change. Tip: as you dismantle the pump, lay all the parts in sequence on the bench & then photo with your phone, so you know the sequence they go back (& which way round).

 

[Blueboatman]

Another tip
The parts are so cheap, from your local bearing and seal shop, why not order 3 x everything?
I did mine couple of years ago, bearings at the same time...

The shaft can be polished at the same time, using a strip of very finest-say 1200g-wet and dry sandpaper, stick the shaft in a battery drill chuck. But you will need a heavy vice and tube drifts IIRC to take it apart /reassembly without forcing the new bearings laterally .

 

[VicMallows]

so you know the sequence they go back (& which way round).

When it comes to seals, I would not advise that!.....the water pump on my brand new factory fresh BUKH had a seal the wrong way around! Not surprisingly it started leaking quite quickly. Just remember that the 'open' side of the seal (where you can see the spring) always goes on the side of the fluid you want to keep out. (I know that for some inexplicable reason this always seems counter-intuitive).

 

[vyv_cox]

Good advice from Vic. In the failure diagnosis course that I co-present we have an example of a pump bearing that failed four times within a very short period. The final one was sent to me for diagnosis. All four had been installed upside-down in a vertical pump. This was done by fully trained technicians, following the procedure of assembling the same way as the previous one came out.

 

[DaveRo]

Is the pump on the GM the same as on the YM?

Just wondered. I spent some time researching these parts for my 3YM30 this year.

 

[JumbleDuck]

Good advice from Vic. In the failure diagnosis course that I co-present we have an example of a pump bearing that failed four times within a very short period. The final one was sent to me for diagnosis. All four had been installed upside-down in a vertical pump. This was done by fully trained technicians, following the procedure of assembling the same way as the previous one came out.

The Haynes manual for a Triumph Herald gives very careful and precise instructions on installing the clutch driven plate correctly, with the shorter end of the hub away from the flywheel. Unfortunately, the shorter end of the hub should be next to the flywheel.