I have a 2004 Jeep Liberty 3.6L. It had a history of the rear pax side brake not releasing pressure, so it would get very hot back there and would wear through pads very quickly. About 3 years ago we replaced the caliper (didn't fix the problem) and then the whole rear brake line. Replacing the brake line fixed it. The thinking then was that there was something in the flexible part of the brake line that wasn't allowing fluid to flow back.

For the past 3 years things have been good with the brakes, until today, the problem came back!

With the caliper being fairly new, and the brake line being fairly new, I'm thinking that it must be the master cylinder, or maybe a valve inside the master cylinder.

I'm looking for advice on what to troubleshoot first. Looking online it looks like the master cylinder might be something I can do in my driveway if I'm careful.

Any advice? Thanks!

edit: Something I read online just now is that failing to open the bleed valve when compressing the caliper can damage the master cylinder. I am guilty of doing this at least twice replacing the pads/rotors myself. Just something to keep in mind if it helps.