Hey everyone I'm working on a friend's 2005 polaris sportsman 700 carbureated last time i had to replace the t fitting in the cooling system because the original had cracked and was leaking he had the head gasket done 2 years ago by someone else now it's leaking coolant out of the expansion tank my immediate thought was bad head gasket leaking compression into the cooling system so I started to do a leak down test on the flywheel side cylinder I took the cover off put it to the 0 degree mark lined up with the cover tdc I'm assuming hooked up the gauges and coolant started coming out of the flywheel cover bolt holes what would cause that? I'm kind of at a loss here I've ridden it pretty hard for 15 mins it didn't leak then as soon as I turned it off it started leaking out of the expansion tank the fan is working it doesn't seem to be over heating what would cause this ive also ran the thing with the radiator cap off until the fan came on to make sure air wasn't trapped in the system from the previous repair any help and advice would be appreciated

 

Chris,
Some Polaris's and almost all side by side by sides it is very hard to bleed the air out of the coolant system.
A lot of them are putting a bleed screw on top of the engine to release trapped air. If you don't, you have a system that won't circulate coolant.

If you don't have a bleeder, jack the front as high as you can get it or drive the nose up a bank. Then run her and fill it there.