Rear brake

[jackrb100]

I am having a problem with the rear brake. When I bleed it completely it gives a decent feel and works well. As soon as I ride the bike on a track it stops working and theres nothing at all. I know it's bled properly because I use a bleeeder connected to a compressor. The caliper has a good piston and seals in it. Maybe master cylinder? Any ideas?

[Baileygunns]

Bent rotor?

[Scro]

Originally posted by Baileygunns
Bent rotor?

That was my first thought.

[xcracer416]

if it was your rotor you would feel the pulsation in the foot pedal right when you hit the brakes, even then you should be able to pump them a could times and still have brakes.

im saying master cylinder has crapped out. after you bleed them have hte rear end in the air and spin the rear wheels looking at the caliper. if its moving back and fourth in a fast consistant rythm then its your rotor

[310ESR]

Rotor

[jackrb100]

The rotor is not the problem, it's perfectly straight. Has anybody ever had a mastercylinder go bad before? If so what were the symptoms? Thanks.