I have a 2005 Pontiac Vibe. I bought it August of 2013 and it was a great car. In December of 2013 I started to experience an issue with the brakes. The front passenger side brake was seizing up and not releasing unless I let the car sit for about 30-45 minutes. My first thought was a bad brake hose. I replaced both front rotors, calipers, pads, and brake hoses. The issue went away for about a month then it came back.
I have replaced a grand total of, (1) set of rotors, (1) set of calipers, (1) set of pads, both front brake hoses, (2) master cylinders, and (2) proportioning valves. This car does not have ABS. For a while when I was having this issue, I would free the line from the master cylinder to the proportioning valve and this would free the wheel. Lately, I have had to free the line from the proportioning valve to the front passenger wheel to release the pressure.
I have not replaced the actual metal brake line yet because I am constantly being told that this is not the issue. Can anyone give me any suggestions as to what may be causing this or if I am missing anything? I've been dealing with this for almost 10 months now and I'm tired of it.
I have recently been told that I should do a complete brake fluid flush of the system in case there are any air bubbles in the line but I'm not sure if this will fix it. I have bleed the brakes every time a part has been changed and I figured if there were air bubbles present, wouldn't it effect other wheels as well? I'm no mechanic so any advice would be awesome.