Hello....I was having some Master cylinder/Booster issues with my '57, so I replaced the Master Cylinder/Booster/Lines/and Proportioning valve....the original set-up was off a late 70's Volare....as was my front suspension....the issue I am having is I cannot get pressure from proportioning valve to the rear brakes....I did bench bleed the Master Cylinder and I have fluid draining in the lines...the fronts brakes work great...the only thing I can assume is I triggered the valve in the proportioning valve...I searched for the issue and some suggestions where to remove the front bleeders and push on the brake hard to recenter the valve...I did also try adjusting the valve itself....the proportioning valve is from CPP....any thoughts?...thank you!...Dan