Yamaha TRX850 Enthusiasts Forum

Interesting one,

I had the tell tale coolant leak from the water pump so I got a kit off Cobba and replaced the seals. No problem there.

Except on replacing the pump I found I had gained an oil leak. Now if you have done the job you will know that the oil is kept in the motor with an o ring and an oil seal on the impeller shaft.

I have pretty much ruled out the o ring as is looks fine and I tried swapping with the old o ring and saw no difference.

This leads me to suspect the oil seal on the impeller shaft.

This is tricky because it is not replaceable without either pulling out the water seal, which will destroy it or pulling out the bearing which will is not really feasible.

The oil seal is strange because it doesn't seem to sit in the pump housing it just floats between the bearing and the water seal. This I supect it the cause of the leak.

Any ideas or comments?

Anyone have a water pump knocking around they could inspect to see if that oil seal floats around in there? You would need to remove the impeller, its held in with just one circlip. With it removed you can see the oil seal.

Photos sent Paul.
Hope this helps mate
The seal sits in behind the bearing pushed into the waterpump body.
If it's floating about I'd say it hasn't seated correctly into the body.

Ok so with further inspection I was able to push the oil seal home without removing the water seal, obviously I should have pushed it home beforehand

Worth noting for anyone else doing this job because the parts are not on the TRX parts diagram and it is a very tight fit. The oil seal needs to be pushed home.

Thanks for Cobba for the parts and for the text messages to help. Cheers mate

My pleasure to help one of the troops