Water Pump Leaks

10 replies to this topic
  • Guest_blatham489_*

Posted July 04, 2002 - 12:07 PM


Can someone confim for me that when coolant is dripping from a ~2mm weep hole just below the water pump cover that it means my water pump seals are gone? It leaks just sitting there cold. I assume I have to take the whole right side of the engine off, clutch included, to get to the backside of the impeller shaft to replace the seal. Anything to watch out for? I already plan to replace the shaft with th e '99 version which apparently has a better wear coating on it.

Thanks for the help.

  • Guest_Guest_*

Posted July 04, 2002 - 12:41 PM


No worries..........
I t is about a $3 fix! :)
just pull the cove and also pull the pump wheel.
carefully pull the seal out with a small screwdriver prying on it.GENTLY!!!!!

To put the new one back in ......I used a socket that was slightly smaller on the o/s dia. to keep it square. tap GENTLY!!!til' seated!
total of about 6buck replacing the cover seal and the shaft seal! :D

  • Thumpster

Posted July 04, 2002 - 02:12 PM


I'll second what Thumpin said. Easy fix. Be careful with your impeller. I got sloppy with a wrench and broke a fin off thus costing me more $$.

  • thumpsalad

Posted July 04, 2002 - 07:55 PM


blatham, also make sure you have the new inner rubber seal FULLY seated in the housing or the bearing will drag against it and won't spin smoothly when the impeller shaft spins!

  • Vanilla_Gorilla

Posted July 06, 2002 - 04:45 PM


maybe you should check your copper washer on the weep hole bolt to make sure it isnt dead. that might be causing a leak. i dont see how a dead seal would cause it to leak from the weep hole. a bad seal would cause coolant to leak into the engine cases, and thus into the oil.

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  • thumpsalad

Posted July 06, 2002 - 04:59 PM



There are 2 seals. When the seal just behind the impeller goes bad, it will drip from the weep hole.

There is a second seal that prevents any of that water (the water that gets by the first seal) from getting into the case. If THAT one goes bad...chocolate milk time in the oil!

  • Vanilla_Gorilla

Posted July 07, 2002 - 05:39 AM


hmm, i was not aware of that. i still am not sure how it would leak from the weep hole, but ill take your guys' word for it. thanks for the correction.

  • Hick

Posted July 07, 2002 - 06:32 AM


Originally posted by Vanilla Gorilla:
hmm, i was not aware of that. i still am not sure how it would leak from the weep hole, but ill take your guys' word for it. thanks for the correction.

From your prior post I wonder if you are thinking the weep hole they are talking about is the same as the drain hole. It isn't.

I think the design was intended to prevent water from getting into the crankcase and mixing with the oil should the (outer) seal fail. So there is a passage between the two seals that leads to a small (about 1 mm) hole in the cases, so water that gets by the outer seal can vent. This way the operator will hopefully note the coolant all over his boot and see that there is a problem, whereas if there wasn't a vent the pressure would eventually overcome the inner seal and the water would end up in the cases and out of the water passages, unbeknownst to the rider.

The outer seal is easily replaced, but to R&R the inner seal you need to also remove the bearing (if I remember correctly).

  • holeshot

Posted July 07, 2002 - 07:29 AM


Yep, same thing happened to me during an enduro two weeks ago. After the event, I checked the coolant and it was a least half gone. :)

Further inpection revealed coolant leaking from the "tell-tale" weephole under the water pump. $2.53 (for the seal) and about 1 hour of my time fixed the problem. The replacement seal had a slightly different design than the original.

  • MotoGreg

Posted July 07, 2002 - 08:24 AM


Did mine after about 1.5 years of use. Now, 2 years later it's leaking again. I just ordered the water seal, the oil seal, and a new impeller shaft. The water seal had a new updated part number. I'm going to change it tomorrow.

  • Vanilla_Gorilla

Posted July 07, 2002 - 09:42 PM


AHHHH, i see what u mean. thanks hick, for the explanation. i WAS thinking about the drain bolt. i get things like that confused at time, cuz i rarely deal with waterpumps at work or on my bike. thanks alot.

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