I have a 2002 mxz sport 600. I'm having an issue with my brakes. When the sled is cold, everything works fine. After about 45 minutes of riding, the brake lever goes to the handlebar, without activating the brakes. I have to pump the brake lever fast to get it to stop the sled. Anyone have any ideas? I'm thinking I just need to bleed the brakes. Anyone have any other things I should check?