Have an 04 non ABS, right front brake gets quite a bit hotter than the left, doesn't pull, IR thermometer shows the right rotor at least 200 degrees hotter, everything has been changed from master cylinder to hoses, calipers, rotors and pads, I'm wondering maybe a defect master cylinder possibly, replaced the right hub bearing but no distance and bearing was fine, 2 shops say they haven't been able to duplicate the problem but ignored the burning pad but not smoking, was told to check the proportion valve, any guesses?

 

On some cars, when the rubber section in the brake line gets old it can collapse or deform enough that it will hold pressure in that even after the brake pedal is released. Maybe try replacing that line.
Also, jack the car upheave someone press and release the brake pedal and see if the wheel turns freely.
Are you sure that when the pads were last replaced that all rust/dirt was removed from all components and that everything was properly lubed, etc?
Perhaps the caliper itself needs to rebuilt or replaced. Corrosion or dirt might be preventing it from releasing
Important: Unless you did the brake job yourself, don't assume that it was done properly and with the needed care.

 

Brake hoses and calipers were also replaced, system was bled after replacing master cylinder, wheel rotates fine when cold, local shop said system pressure was good.

 

That's the problem: "were replaced" "was bled" "local shop".... But the brakes are still messed. Best to learn how to do this stuff yourself, it's a hassle, but very rewarding to fix a car yourself. However, it that's impossible, maybe try another shop, and hope for the best.

 

I usually do all these things myself but broke my foot halfway thru so had to use a shop that I've used before, the mechanic that looked it over this week thinks it may be the proportion valve

 

Could be, I suppose. As you prolly know, there's lots of good vids on YT about this stuff, and you can pick up good used manual online for. a couple of bucks.

 

Problem was the proportion valve, these have 4 lines going to each wheel after it leaves the valve, could not find a new one so had to pull a used one and it was good so this problem solved.