[hiddenpants]

havent looked at the breaks on my mustang but on the dodge dart i had before the ebrake mechanism on the rear calipers have these rubber boots that cracked and let a ton of dirt into the mechanism and that locked it up on that car. burned completely thru a brake rotor, the disk was less than a 16th thick and cracked off, the ebrake failed 4 hours from home and i just powered thru and figured i would fix it later

probably not your problem but if everything else is fine maybe check the calipers themselves