Presumably you get fluid out of the bleeder when a helper pushes the pedal. If not, try removing the bleeder all the way, just in case it is clogged w/ gunk. If the caliper still doesn't retract, sounds like it must be a bad caliper, since there would be no fluid pressure inside. Stainless Steel Brake Co. got their start by retrofitting stainless parts into the Mustang and Dart K-H calipers, since jamming rusted pistons was a common problem.
