yes the pistons turn to go back, instead of just pushing back like front disc. sounds like the master cly has the rod stuck wide open, does the bleeders have any pressure when bleading them or is it more like a drip? or just a little squirt? i woukld remove the master cly and replace it. and make sure you bleed the new master cly before the install
http://home.earthlink.net/~saawatson/ my 1983 trans am. PONTIAC POWERED