I got another question for ya'll. It's probably just ignorance, but if a leaking master cylinder isn't the root of my weak brake issue, what could it be? My set up is power brakes disk in front drum in rear. I am running the stock master cylinder for now, but am about to do the upgrade to a corvette one. I have good pads on all four wheels, I bled each line individually, and checked all components for anything worn out or broken. Nothing but the leaking master cylinder. My only other thought is that it may have something to do with the vacuum lines leading to the brake booster. Those may be leaking. I have yet to mess with them. For the mean time, I put the brake pedal to the floor and run backwards through the gears using the engine to help slow me down.