Seeping water pump

[zod]

Finally my bike is back to normal ticking .
But now there is a small, but steady seeping/dripping of water from behind the water pump.
After a long standstill I'm now hungry for some time in the saddle so I hoped I could order the needed parts without pulling the pump of the bike.

After what I can understand it's probably part 14 (x2) that has to be renewed?? Is this the seal you have to buy from the YZF parts list?


.

[Mincehead]

The O rings?
Yes very likey it`s them or perhaps just one of them.Beware the condition of the small pipe stub (13) if it`s anything like the coolant stub that`s secured to the cylinder head it`ll be likely to have rotted/corroded.
It may well be the stub pipe growing in diameter through corrosion that`s caused the O rings to leak.
They are likely standard O rings so you might be able to buy them in any motor factors rather than through Yamaha, of course you need to have one in your hand first to guage it`s size/dimensions.

[Kevtrx849]

Take care when you remove the pump as theres a washer that can drop into the motor if you remove it too fast. Part #9.

[HansJ]

There's also another culprit, which can't be seen on the picture (probably because it's not sold as a separate part for the TRX/TDM). Ask to see the similar pic from a FZR1000 (i have heard many "early" Yamahas had the same part) instead. Then you'll find a small springloaded "tube" with a radial Teflon/plastic glide surface. This was broken on my bike, and could be ordered as a separate part as long as one didn't say it was for a TRX...

[zod]

Thx for the input!
I have investigated the leak some more and in the end removed the water pump.
Tracing the leak made me quite certain it comes from the water pump shaft area. It is impossible(?) to observe this directly as long as the pump is mounted on the bike, but I could see no water coming from anywhere else.

My main suspect is now the special spring loaded tube-thing, HansJ describes in his post.
I guess the water escapes the "tube" and runs through the hole seen in this picture from the Haynes manual:


I'll take a trip to my local dealer tomorrow and have a look at the fzr1000 microfiche.

[Mincehead]

Yamaha do not generally list the ceramic faced spring loaded rotary seal Zod, instead they sell you an entire pump!
I repaired the pump in my XTZ engined Skorpion myself, after finding that Yamaha wanted to charge my something like 192 quid for a complete pump.
I visited a local pump spares company with the sprung rotary seal and they found something similar for me, it was not a direct like for like fit though and I used another O ring inboard of the lip seal that runs on the impellor shaft to ensure it remained watertight.
Done thousands of miles since with no problems what so ever.
If an FZR 1000 ceramic seal is available I`ll be most intruiged and who knows it may even fit the XTZ pump if it goes again in the future.
If I had not been able to repair my mechanical pump I would have simply fitted an electric coolant pump and blanked the entire gear driven pump off at the crankcases, there would be a little saving on power absorbtion from the motor too, it all takes horsepower to drive you know.

[Wombat]

Yep, they either leak oil or water. Mine started leaking oil and started getting gradually worse. My mechanic did a bodge job which made it leak even more!

Ended up getting a new one ($300+) and hasn't leaked a drop since (but saying that, it probably will now)

Bob

[zod]

Ended up buying a used TDM pump from the ebay. Waiting for it to arrive...

zod

[arnoldlayne]

Dead thread revival:

Just had rebuild my water pump to fix a minor coolant drip from the weep hole on my TRX850 . As mentioned above Yamaha doesnt list the mechanical seal as a separate part for the TRX, they suggest the whole pump at ~$350.

I think its an oversight in the parts manual as there is, no need to buy the whole pump. Yamaha part number 11H-12438-00 is the correct 'water-side' mechanical seal and fits perfectly, these are readily available on the aftermarket for around $40. Be very careful fitting them as the seal faces are extremely delicate.

For oil leaks, the body oil seal is just an O-ring, but it is an odd size. Any hydraulics shop should be able to help if you take the pump body and old o-ring in with you. Remember to get an oil-safe material (NBR, Nitrile, Viton etc.). There is a shaft oil seal that sits between the 'water side' mechanical seal and the bearing. This seal doesn't come with the 11H-12438-00 kit, lucky mine was in good nick. if you need one, perhaps a hydraulics shop could help?

[Wombat]

Looks like water pump coolant leak number 3!!!!!!!! First one (original) lasted 12 years, second one 2 years, this one only 18 months!
Have to watch and monitor this one. Feel like sending off a rather nasty email to Yamaha Japan saying what a CRAP product this is!

Bob

[bane]

Dead thread revival:

Just had rebuild my water pump to fix a minor coolant drip from the weep hole on my TRX850 . As mentioned above Yamaha doesnt list the mechanical seal as a separate part for the TRX, they suggest the whole pump at ~$350.

I think its an oversight in the parts manual as there is, no need to buy the whole pump. Yamaha part number 11H-12438-00 is the correct 'water-side' mechanical seal and fits perfectly, these are readily available on the aftermarket for around $40. Be very careful fitting them as the seal faces are extremely delicate.

For oil leaks, the body oil seal is just an O-ring, but it is an odd size. Any hydraulics shop should be able to help if you take the pump body and old o-ring in with you. Remember to get an oil-safe material (NBR, Nitrile, Viton etc.). There is a shaft oil seal that sits between the 'water side' mechanical seal and the bearing. This seal doesn't come with the 11H-12438-00 kit, lucky mine was in good nick. if you need one, perhaps a hydraulics shop could help?

Dead thread re-revival:
My water pump started leaking coolant last week...

Option 1-A new pump ordered from Japan, 2-3week wait and $400.
Option 2-Yamaha part number 11H-12438-00 (mechanical seal) $27 + 93101 12173 00 (impeller shaft oil seal) $8... or pick up an oil seal from your local seal shop in size 12-21-4 for about $5.

I went with option 2. Back on the road leak free for under $50 ( had to buy some cir-clip pliers).

cheers,
Bane.

[daves96trx]

Hi all,

this is my first post! Wooo!
My mechanic tells me I've got exactly the problem you've described here. We discussed the mechanical seal, but couldn't see it as a replacement part in the diagram I found. But if you reckon this works, I'll totally give it a shot! (Unfortunately I don't have the skills to do it myself...)

Other options are -
Option 1 - genuine part from his local (Sydney) supplier in excess of $500.
Option 2 - new (aftermarket) part from US - $350AU by the time it gets here.
Option 3 - complete part from the wreckers in Sydney - $125, but not sure of it's condition.

If the mechanical seal fix doesn't work, for whatever reason and I need to get a whole new part...
Can anyone confirm if indeed the 96 TRX* engine share most of it's parts with the TDM 850? And if so, is it relevant what year model the TDM 850 part is - they either seem to be 1993 or 2001.

(*My 96 TRX is a Japanese import and according to the import plates it's actually '95, but no one seems to refer to it as that...)

Cheers!