binding brakes on 78 z650 B1 - single disc -

The front brakes on my 78 Z650 B1 (single caliper,mounted in front of the fork leg) were binding - i rebuilt the master cylinder - no change, replaced the caliper piston and seal, replaced the line - when assembled the caliper slides freely back and over on the caliper mount - wheel turns freely - put a few miles up - use the brakes - presto it binds up again - any ideas ?

When it binds can you still slide the caliper in the mount? How do you "un-bind" it? I'm wondering if there's an issue between the pads and the rotor. Ed

the caliper locks up tight - have to open bleed nipple - it has even tightened at the lever.

im stumped !

Inside the M/C there is a little bypass hole. Sometimes they clog up with crud or old fluid. Tiny about the size of a needle. I always take a metal strand from a wire brush and poke the hole thru. It is hard to see but if it is clogged it will not release the pressure inside the cyclinder. You can check it with the cover off. If you poke thru be sure you don't hit the rubber inside the cyclinder. It's best to do this when the cyclinder is out.

M/C is coming off this evening and will give it one more go, after that its off to the breakers in search of parts - thabnks for the tip - will let you know if i have any success!!

Well - Hats off to you - it really is a tiny - tiny - tiny little hole isnt it!!. M/C stripped - hole cleaned out - all reasembled - working a treat. Once again - Cheers for the help.