After changing the coolant on my 09 XT660X I noticed that the cap on the rad was really loose. It isn�t leaking coolant, but after putting the cap back on I noticed a loud rattle from that area of the bike in 1st and 2nd gear. I can only assume it�s the loose cap. Anyone else had this problem? I know faulty caps are common in some XT�s.

when you put it back you should have to push down somewhat, to feel the spring is holding it under some pressure.
if you don't have any pressure, the cap won't close and spray the coolant as soon as it gets hot...

its a bit like a medicine bottle with the child safety cap..it pushes down and turns...as said.

I spent a while fiddling around with it, turns out that the metal seal had bent so I bought a new one and now it�s great.