Brake Residual Valve

[dustin72]

I just finished installing a Wilwood manual master cylinder/adjustable proportioning valve assembly and have bled the brakes many times. The pedal seems to travel quite a bit and feels spongy. If I pump the brakes, the pedal becomes firmer. I think I need the 10lb. residual valve that Wilwood recommends with rear drum brakes but I've read that some people didn't need to install one. If I do need to install one, can it be installed on the outlet of the proportioning valve to the rear brakes? Thanks.