I replaced the master cylinder bleed the whole system. the old fashion way with the help of a friend by pushing peddle down cracking bleeder screw. start rear right,rear left, front right. front left. start car put in gear will not move brakes dragging real bad.go to right rear open bleed screw to relieve pressure. till rotor turns. do the rest of the brake cylinders. all wheels turn by hand while on jack.start car put in drive same thing brakes drag car will not move. peddle feels fine. push down peddle returns normal.i bleed the whole system a second time with mighty vac. the same thing happens. brakes dragging bad. peddle feels normal.push down does not feel spongy and does not go to floor. and returns all the way up. normal.