Left caliper keeps locking up, I've bled it twice before thinking the offroading was gettin mud in there, and it fixed it. Well this time they are staying locked up.... Symptoms- bleeds fine pumps the fluid right out and rotor spins fine, but the second I tighten the bleed valve and apply any pressure the pressure stays and the rotor dont turn,....is this the combination valve or master cylinder and can i fix it or are we talking whole new unit?
I had some thing like that happen to me on an old truck I had in high school. The master cylinder had goo in the bottom of the resvewar. Keeping the pressure on the rotor but the break fluid was able to bleed out. It would bleed very slow, So to make sure I had all the junk out of the break system I had to replace everything and I used rubbing alchol to cleen the break lines. My shop teacher said the the goo in the master cyclinder could be a sign of more break problems so I might as well start with a fresh new system so I would be able stop properly. He also told me if the master cilinder was bad to go ahead and change everything else. Because it wouldn't be long before something else in the system would give out or vice versa. I don't know if that helps any.
I'd be suspiseous of a rubber line. Break the joint at the "input" side of the rubber line. If it doesn't release, bad hose. Check your master cylinder to see how many lines come out. If there is only one going to the front brakes, a M/C problem would probably show up in "both" sides.
OK I think that your right I replaced the caliper just cause it looked bad and I took off the rubberhose and thats where the problem lies but its weird fluid will go one way through the line just not back up the line.