Cannondaleriders

Jess,
If your fluid is more than 3 years old change it! Also make sure to use the right fluid. Do not mix Dot 3, Dot 4, and Dot 5. I use Dot 5.1.

To others,
Sounds like your brake fluid may be boiling or breaking down. Just because it was cool out, doesn't mean that your brake fluid was cool. The brakes will generate heat no matter what the outdoor temperature is, just like the motor.

Also check for air leaks, that the caliper and piston move/slide freely, and that the rotor is mounted securely.

It wouldnt because the pads were grabbing air rather than the disc.They only move a little bit when you hit the brakes if the distance to where they grab the disc is greater than the little they move you get nothing.

CraigC
A thin disc probably cant take as much heat like Wannablaze said.I could see it warping when it got really hot and causing those symptoms.

Not to poop on anyones theories, but boiling the Fluid is highly unlikely. Unless you don't ever take your foot off the brake. Front brake problems.

1. If you bump the brake line sometimes it causes a brief leak too. Not enough to stay steady and loose all fluid, but enough to cause a breif loss of pressure.

2. What C27 said!

3. Last, but not least. What I think may be Sac's problem...Look at the plate on the Caliper and squeeze the brake lever. If the whole caliper is moving then you bent the plate the caliper mounts too. I have had this happen several times. A little prying will straighten it out to make it workable.

As for the rear brake not sure where to go there that hasn't been suggested!

Check out these links for an explanation of the different rated brake fluids. Most people don't understand the difference in the ratings.

http://www.shotimes.com/SHO3brakefluid.html

http://www.xs11.com/tips/maintenance/maint1.shtml

Thanks for the links to the Brake Fluid info... I never knew the difference.!!