450 SX Coolant Leak from Head

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450 SX Coolant Leak from Head

Post by 4Strokes » Thu May 26, 2016 1:26 pm

Topic: 450 SX coolant leak from hole on left side of head
Author: Devin
Posted: 09/28/2007 7:30:27 PM

I just picked up my 03 450 sx and was looking it over a little better in the garage and when I first started it I noticed a little bit of rad fluid coming out of a hole on the bottom left side of the water pump(I think its the water pump). It is just to the left of the fuel on off switch. I cleaned it out with a small screw driver and it feels like it would gop up quite a ways.. After it is running for a sec no fluid comes out but a little bit of steam does. Anyone know what this is or is there suppose to be a hose hooked on to it?

Reply by b_king on 09/29/2007 08:34:22 AM
Possible an overflow release of some kind? The BMW 650's have a check that will leak either coolant or oil because there is a two way seal separating the coolant and oil at the waterpump. This check oil allows to know what side is leaking before they start to mix. Maybe this is something similar..not sure. Call up a KTM dealer, they should know. Good luck!

Reply by 250f canuck on 09/29/2007 08:35:30 AM
I'm pretty sure a shop manual would know. If the bore of the hole is threaded then there should be a bolt, if not then no bolt.

Reply by kaiser173 on 01/12/2008 5:16:39 PM
on Honda it means the seal is blown is there coolent in your oil?

Reply by dunerider525 on 11/20/2009 2:19:57 PM
the small leak is the most common thing among the 525s. it not much to worry bout unless it starts to eat up your coolant. keep an eye or two on your coolant level, that will determine the severity of your leak. they sell a kit for the problem and it a do it yourself kind of thing if your a handy man. should take less then and hour. basically the leak is from and O-ring that seal the water pump. go to this link and check it out:

through this video u can get that website and order the kit and of course the video will lay it all out.

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