[Glyn]

can some one comfirm that my rear brake master cylinder is dead

after riding bike home noticed the power felt down quick check revealed rear brake binding
took caliper off the bike and removed pads, every thing looked good
the pistons moved in and out o.k but the fluid wont go back to the master it just pushes the other piston out.
the only way to get both pistons to return was to loosen of bleed nipple. they both moved home freely then.
so it looks like the fluid cant return to the master
its not an over adjustment of the pedal as i removed it just to check.

so is the master cylinder servicable
if not any body got one