07 WR450f coolant leak

8 replies to this topic
  • Andot09

Posted June 09, 2009 - 03:24 AM


Hi, i took my second hand 450 for its first ride the other day and noticed that as i started it there was a coolant leak on the right hand side of the bike. I imagine from my reading that this is simply the weep hole telling me my pump shaft and seals are gone. However, this leak seemed to stop or atleast slow dramatically as the bike warmed. My issue is that the bike seems to be using all the coolant in the overflow bottle. After a few hours riding the overflow is empty again. Is this normal or do i have other issues? Thanks

  • klossWR450

Posted June 09, 2009 - 11:27 AM


what drops out through the weep hole is refilled from the overflow bottle, you will have to replace the water pump seal soon

  • Strattos

Posted June 09, 2009 - 03:12 PM


Just replaced my water pump seal two weeks ago. It's a quick half-hour job. Have a good look at the shaft as you might not have to replace that.

I did a TT search when mine went and there are guys who just did the seal who have been going for ages with no problems since. As above re the coolant coming out of your overflow bottle.

  • Andot09

Posted June 09, 2009 - 11:31 PM


Thanks guys. I'll replace the seals and check the shaft and see how it is after that. But how do i know if the shaft is bad?

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  • klossWR450

Posted June 10, 2009 - 07:45 AM


if it's bad you'll see grooves where the seal touches the shaft

  • Andot09

Posted June 11, 2009 - 11:10 PM


ok thanks a heap. I'll give it a look.

  • TommyTheKid

Posted June 12, 2009 - 01:47 PM


Wait, I don't have coolant in my overflow bin, I thought that was only used when things got too hot, then it drained back into the rads when it cooled down?

EDIT: I just got my water pump shaft/seals replaced as part of a greater rebuild as well too.

  • klossWR450

Posted June 12, 2009 - 02:23 PM


Tommy, it works as you said unless there is a leak (or you've boiled couple of times) and than radiators start "borrowing", there is a line at about 1/3 volume on the overflow tank that suggests healthy/minimum level I believe

  • Andot09

Posted June 15, 2009 - 02:52 AM


Yeh, i think it basically works so if or when coolant evaporates, it is sent to the tank to cool down and liquify whilst some is drawn from the tank to take its place. I try to keep mine at the mark


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