1991 Other Ford Models brakes

If the master was replaced, you probably still have air in the system, Bench bleed the master by getting brass plugs and screw them into the two ports, then pump the master until you cant move the piston any more. Attach the lines, Have an aide press and hold the pedal crack the lines and retighten, repeat this till all air is removed at the lines, Don't let the master run dry, bleed rear cylinders by opening the bleeders and wait until the fluid dripps out. Close bleeders. Make sure the rears are properly adjusted, then test the pedal hieght, you don't need to remove the master at this point. Just the lines, and then plug and pump.