04 yz 450 f weep hole questions..please

5 replies to this topic
  • macoroniman2004

Posted December 17, 2013 - 04:31 AM


Ok here goes im really hoping to hear from gray looks like you know your stuff...(ive been stalking posts) lol..any ways I have a 04 450 and went riding while it was cold out and next morning woke up to coolant puddle in garage...
Filled coolant only about a inch low in rad..
Ran till warm and noticed drips from water pump weep
Replaced seals and bearings did not notice a groove in shaft looks ruff but finger nail wont catch
So re installed everything filled fluids and ran until the rad spit a little coolant out overflow no air moving didnt take long..
No drips now only a tiny amount of dampness inside weep none dripped
Question is ..is this normal when the bike gets hot??
Could it be residue inside pump cavity?
Really need some advice cause im a nervous nelly when it comes to maintenance lol
Balancer bearings were also tight not sure how to check them with gears on..
And finally should I get the new shaft? Note that oil was clean with no milky ness
Thanks in advance to any info to help this the first ever yammy ive owned and don't want to spoil it with a engine rebuild lol

  • macoroniman2004

Posted December 17, 2013 - 08:28 AM


Any one? Lol

  • grayracer513

Posted December 17, 2013 - 11:37 AM


Not very patient, are you?


Any time you support a shaft with ball bearings, you have to have two of them.  There's only one on the shaft, so what the engineers did was to plug the shaft into the end of the balancer shaft, and that way the balancer shaft bearing provides the second bearing support for the impeller shaft. 


Plan on replacing the shaft, and while you're inside the engine, check for an excess of play in the balancer shaft bearing on that side.  If it's loose, it can cause the impeller shaft to wobble in the seal and leak.  Probably a matter of a worn shaft, or, you may have put the seals in backward.


Read: http://www.thumperta...0-coolant-leak/


And: http://www.thumperta...ter-pump-seals/

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  • macoroniman2004

Posted December 18, 2013 - 04:29 AM


Ok read both articles...do u have to remove the balancer gear to check the bearing or will it wiggle with gear on?
I had zero play while checking with gear on shaft
Maybe I just need a new impeller shaft?
Thanks again in advance!

  • grayracer513

Posted December 18, 2013 - 07:32 AM


Ok read both articles...do u have to remove the balancer gear to check the bearing or will it wiggle with gear on?


Vertical clearance in the bearing should be detectable with the gear in place. 

  • macoroniman2004

Posted December 18, 2013 - 08:11 AM


Ah cool thanks very much for the help looks like I need only a impeller shaft ! Wont really know till the snow melts any ways! Happy trails to all

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