A little help please. I am trying to finish my restoration and I'm down to the brakes before I can go for a test drive. For the last several days I have been trying to get the brakes to work. I have bled the four wheel cylinders at least 6 times all around. I don't believe there is any air in the line but I still have a soft pedal. If I pump the pedal 6-10 times the pedal firms up a bit but 10 minutes later........no pedal pressure and I have to pump the pedal again. Should I recheck the brake shoe clearance and recheck the pedal to floorboard clearance on the backside? Any thoughts from anyone on what is my problem?