I have a 1973 pontiac ventura that came with disc/drum brakes. When I bought the car it had been switched to disc/disc, but they didn't change anything except the brakes themselves. I have since purchased and installed a disc/disc master cylinder, all the brake lines, and bled them repeatedly! I was told by a rod shop that my only problem would be that I might have too much pressure to the rear. Well, I don't seem to be getting enough pressure to anywhere. They won't pump up very much at all and they don't seem to be catching in the rear at all. I don't know if it matters or not, but it has power brakes, should I be bleeding the brakes with it running because the brake booster? I would really like to drive this car before winter, so any help would be appreciated.