Issue : Brake pedal goes down about 4 inches until it starts firming up. Then brake light comes on and stays on. The brakes will eventually work but they are very hard and only after all the fluff at the begining. Parts Replaced: -Master Cylinder -Brake Booster -Brake Lines (Longer SS Lines) -Front Calipers and Pads -Rear Wheel Cylinders I've bled these through two quarts of fluid so the fluid is pretty new, but it doesn't make a difference. The next step is replacing the proportioning valve but I'd rather not unless I have to. Any thoughts???