I have brake problems on my XJ 650, the front brakes are tight and get tighter as they heat up when I ride. I have rebuilt the master cylinder, changed the fluids, bleed the lines, and the system works fine at first. With a few pumps of the hand lever the brakes tighten up and do not retract until I loosen the line from the master cylinder to relive the pressure. Rumor has it there is a small back bleed in the master cylinder to relive the pressure from heating in the wheel cylinder.

Is this true? How small is it? I have probed around with a single bristle of a metal brush and have not found the opening and do not see it on the inside bore of the MC.

What do you think?

Thanks

Well it's like this.

There is a hole and I needed to drill it out with a brisel of a wire brush.

Problem solved............

Brake caliper seals?