coolant leak (new bike)

5 replies to this topic
  • victor

Posted February 02, 2005 - 03:38 PM


i just got a brand new out of the crate leftover 2003 yz450f,i have not even ridden it yet,from the day i brought it home if i start it and run it for a few minutes and shut it off it leaves a small coolant puddle under the bike,i see that its coming out of the weephole under the water pump.

now the bike as i stated is spankin new,i watched the dealer uncrate it and put it together so there cant be a worn seal or or any other worn part for that matter

could it be that its been about 15 degrees out(I'm in NY)and the cold may have shrunk the seal a little and it will stop after some riding

or could a overfull radiator cause it

i have had 2 other 4 strokes and many 2 strokes and i never had a coolant leak,weephole or otherwise so i cant see why it would happen on a brand new bike

any help will be greatly appreciated :cry:

  • Butta

Posted February 02, 2005 - 05:25 PM


It's covered under a 30 day warranty...take it back and make them fix it. Chances are, that if it's been sitting for awhile, the seals are dried and useless. They'll have to replace the water pump seals. Hope no other seals are in the same condition......

I would ride the hell out of it for the warranty period, just incase there are more problems associated with sitting for so long.

My $0.02

  • WRookie

Posted February 02, 2005 - 05:44 PM


It's normal. The bike wasn't designed to sit and idle. It needs to move to have airflow through the radiator. Keep it in mind when you are out riding. If you are going to stop for mor than a minute you should kill the motor.

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  • WRookie

Posted February 02, 2005 - 05:48 PM


OOPS. I re-read your post. I didn't see that you said coolant is coming out of the weep hole. New seals are needed as Butta said.

  • Frostbite

Posted February 03, 2005 - 06:57 AM


If it’s coming out of the weephole, then the seal is bad. The seal may have dried out or the shaft may have corroded from sitting so long and then damaged the seal when you started the engine. There are 2 seals on the waterpump shaft, one holds back oil and one holds back coolant. I’ve replaced mine a few times and always replace both. I also replace the shaft. The first time I did the seals I left the old shaft in and the coolant seal didn’t last a month.One TT’er suggested putting a dab of grease in the weep hole after you put the new seals in. this will help keep crap from getting in through the hole but should be easily displaced if coolant or oil leaks past a seal. It sounds like a good idea to me.

  • victor

Posted February 03, 2005 - 02:58 PM


hey thanks everyone for the help,i called the yamaha dealer and they are going to replace the seals(the bike is still under warranty)and while its there im getting the gytr offroad flywheel installed,i'll let you guys know how it turns out :cry:

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