My '34 coupe has a Corvette power MC mounted under the car (typical for a street rod) and works fine under most circumstances. However, in a panic stop situation, it doesn't work very well. I have to use a lot of pressure on the brake pedal for it to stop, almost like

I don't have any power assist. The rest of the system consists of Granada disc with GM calipers up front and Corvette in the rear. A 10 PSI residual

valve in line for the rear brakes (which what was recommended) but not for the fronts. Everything is new with only about 1000 miles on it. It has done this

since the car was built. The other day I almost hit someone in a panic stop so I would like to get this fixed ASAP. What could cause this?