hello , i have a 1939 chevy 1.5 ton truck , updated to all 4 wheel disc brakes with a single 7 inch brake booster master cylinder combo 1 inch bore mounted under to floor board from speedway motors . the vacuum line is hooked up to the intake manifold small block 350 . i have bench bled the master cylinder 2 times and 1 time in the truck , installed 2 lbs residual valves 1 for the front and 1 for the rear, i have bled all 4 ports starting with the farthest .I can not get any pedal only if i pump the brakes 3 or more times then they are spongy . while the master cylinder is still in the truck , i closed both ports of the master cylinder and stepped on the pedal , good firm pedal goes down 1/2 way to the floor . i have jacked the truck up 1st the front bled the brakes and jacked up the rear and bled the brakes making sure the master cylinder was the highest point in the complete system . no leaks any where in the system . any help ? thank you for looking at this thread . 1pete1
