Blown water pump seal

4 replies to this topic
  • thumpsalad

Posted March 08, 2002 - 08:24 PM


Today while prepping my bike (99 YZ400) for a ride this weekend, I noticed after running the bike up and down the block that there was a little bit of coolant seeping from a small weep hole under the impeller housing. Does this mean that coolant is leaking past the first seal behind the impeller? The shop manual I have shows everything, but does not explain the hole or any symptoms.

Any help is appreciated!

  • Guest_Guest_*

Posted March 08, 2002 - 08:41 PM


It is just dripping out of the "weep" hole.
<center><font color=blue>NO NEED TO WORRY</center>
It cost me a whopping $5 for the water pump gasket/o-ring and the shaft seal!
It took me about 20minutes to fix from start to finish and it was my first time.
Just take off the cover to the pump...( use a bucket to catch the fluid)(unless you have cats!!
:D )
<h2><font color=red>GENTLY</h2>pry out the old seal.
In order to put the new one in and get it SQUARE into the hole, I used a socket that fit was slightly smaller than the outside diameter of the new seal and tapped GENTLY!!!!til' it was completely inserted.
<font color=blue><h3>VERY SIMPLE</h3>

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  • dkwok

Posted March 09, 2002 - 01:49 AM


u need totakeout theright sidecrankcase cover to access the impellershaft & change the 2 seals.

[ March 09, 2002: Message edited by: dkwok ]

  • thumpsalad

Posted March 09, 2002 - 07:57 PM


Turns out the first seal was toast, but the second was in good shape. I ended up replacing them both and inspecting everything else while the clutch-side covers were off.

Glad I didn't turn my crankcase oil into a milkshake! :)

  • Guest_Guest_*

Posted March 09, 2002 - 08:20 PM


That is why they put that WEEP hole there!!!

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