Having a problem getting a firm brake pedal. I have a dual compartment 67` mustang MC mounted on the frame, all 40` ford brake parts. Have a 10lb residual valve for the rear brakes(have ordered one for the front). Have bench bleed the MC twice and the lines 3 times. The brakes are grabbing but the peddle travels 3 to 4 inches before it does grab and it is only 2 inches from the floor boards. Any idea how I can get the peddle to grab sooner?