Rear disc brake bite point moves

darmelabi
darmelabi Posts: 19
edited May 2008 in MTB workshop & tech
Hi

I have a problem with my rear Avid Juicy 3 disc brake.

In order to get my bike out of my house I get it up on the back wheel (not with me on it!) and "wheelie" it along. It's probably only up on the back wheel for about 30 seconds and during that time I have to use the brake. Believe me, it's a lot easier than carrying it!

What I have noticed is that the point at which the brake pads hit the disc (normally half way down the brake lever travel) moves and can usually end up that the lever hits the handlebar grip before the brake works. If I keep the bike up like this and pump the lever, I can actually make the brake stop working altogether.

If I then put the bike back down on to two wheels, and pump the lever, the bite point comes back and after about a dozen pumps, the brake is back to normal.

I've tried this on the front brake but there is no effect.

Is this normal? The bike is new and this is the first time I have had disc brakes. The bike came from an insurance claim so I'm not in contact with my local bike shop - yet! Any ideas?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    you have air in the master cylinder. get a bleed kit and suck the air out and replace with fluid.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown