After 3 laps today I found it difficult to move slowly or pull away. I couldn't turn the back wheel by hand and there was no resistance at the pedal. Riding back to the car the disc heated up and is now "blue". After getting home and the bike cooling down it's now freed up. As there was no resistance at the pedal could it be the master cylinder that stuck? Now it's freed up there is resistance.

Thanks in advance

Carl

Sherco 290 2010

 Chances are it slowly heated up during the event. I would install new pads and back off the adjustment to make sure you have some free play. You are lucky it did not catch fire.

Insure there is free play in the pedal linkage so the MC piston may return fully and allow backflow of fluid as it heats up and expands.

 

A damaged outer seal on the MC may allow mud/ dirt to pack up in there and block the piston travel as well.

Thanks both I'll take the master cylinder off and check it. I was aware of the possibility of fire or warping the disc so I rode slowly back to the pit.

So I found a few problems with the rear brake. The pads were almost worn out causing the piston to come out too far and stick. The needle roller bearing in the pedal was gunked up and almost seized causing a sticky pedal and the hose from the reservoir to the master cylinder had worn through on the engine. All cleaned, greased , repaired and new pads fitted. System bled and now I have a back brake I hope. (Not ridden yet)