78 Chain drive single rear disc. RH. My rear master cylinder builds up pressure and doesn't release. I will bleed the pressure at the caliper and then it seems to work for a while, a couple of hours of riding stop and go, and then pressure builds up again. Has anyone seen this? Will a master cylinder rebuild kit fix this? Is it rust, debris? Not able to find an OEM replacement. Would prefer to avoid modifications to accommodate a different make or model master.
Last edit: 24 Aug 2015 16:08 by gotmoto. Reason: Mis-spelling
sounds like your return port is clogged. take apart the master cylinder and look at the VERY tiny hole. make sure its super clean. since you're in there i would take apart and inspect and clean the entire MC and caliper.
+1 on that. Pull it apart and give it all a good clean.If youre careful you might get away with reusing the rubber bits and not need a rebuild kit.
If not,a rebuild kit isnt expensive and worth fitting for peace of mind if nothing else.
Good luck
