04 yz 450 f weep hole questions..please

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

Any one? Lol

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.thumpertalk.com/topic/841710-04-450-coolant-leak/


And: http://www.thumpertalk.com/topic/691433-repeat-failures-of-water-pump-seals/

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!

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. 

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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