I just had some problems with my brakes. I started with plugging the master cylinder and working my way back till I found the right rear caliper was bad. I put seals in it & checked it from front-back and could not find what the problem was with it. The UPS man will be coming tomorrow.
I guess all I should have said was start at the master cylinder & work you way back blocking off everything till you find the problem. I used 2 cans off Wilwood Hi-Temp 570 not finding the problem before doing it that way. GOOD LUCK!!!