Water Pump Seal Problem

2 replies to this topic
  • scottyp

Posted March 17, 2005 - 12:47 PM


Ok, I pulled out my '03 wr450 a couple weeks ago to get ready for riding and, after dewinterizing and starting, water started leaking out the weeper hole in the water pump. So, of course I did a search and found all the info I needed to fix the problem. I replaced the two seals and the impeller shaft as recommended, flushed the system, and put in Enginge Ice for coolant. Started her up and after about three minutes of idling (to check the oil level) coolant starts spilling out the weeper hole worse than before. I decided the seal just might need a little running to get oriented and seal up so I took it up and down the street a bunch of times. No luck.

So, I went and got another water seal and did it all over again. This time I carefully inspected the impeller shaft for any irregularites or burrs and made sure the bearing and both seals were seated properly. Again the leaking restarted after a few minutes idling. I drove it up and down the street a few times and it quit leaking. Went out for a ride the next day and noticed a few drops were coming out here and there, but nothing too big. The second trip out, the bike again started leaking pretty good for the first few minutes then slowed to just a few drips here and there. After 4-5 hours of riding I went through 3/4 of the fluid in my overflow tank. I would really like to quit buying Engine Ice at $16/half gallon. Any suggestions on how to fix the problem short of just plugging up the weeper hole?

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  • Frostbite

Posted March 17, 2005 - 01:02 PM


The same thing happened to me after installing new seals and shaft. I had one of the seals installed backwards. The seals go in with the flat side/serial numbers facing the weep hole, so when they are installed they are opposite to each other, with the flat side/serial numbers facing together. That way when pressure builds against the hollow side of the seal it pushes the lip of the seal tighter against the shaft. Installed backwards, pressure pushes the lip of the seal away from the shaft.
The oil seal probably wouldn't leak if installed backwards since there is no pressure, just an oil bath. The coolant seal is under pressure as the bike heats up.
When you are pressing either of the seals into the case, the side of the seal with the coil spring shoud be facing out towards you.

  • scottyp

Posted March 17, 2005 - 01:41 PM


Thanks Frostbite. I definitely have the water seal in backwards. I put it back in the way the original was, but that was probably why the thing was leaking in the first place.


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