If the brakes were locking, you may have had no free play in the adjustment rod. Remove the brake lines from the master and get the bleeder fittings with hoses that would go in those two holes and bleed the master by it's self. Then proceed from there with connecting the lines and bleeding and keep the master full of fluid at all times.
This type of bleeder screws into the brake line hole and the hoses go into the fluid reservoir so air isn't sucked back in. As you cycle the master cylinder you should start to feel resistance and the fluid returning to the master reservoir will be free of air. Be sure there is a little free play in the linkage when done and that the master cylinder plunger is not tight against the linkage. It has to be able to come all the way out. If the plunger is held in slightly, all of the fluid wont be able to return to the reservoir and pressure will build up in the system holding all the brakes engaged.
