I have a 1948 GM Velox - I am running mitsubishi L300 front end with discs and borg warner diff (chrysler) with drum brakes. I am reaching out because I simply can't seem to get the brakes to bleed and firm up. They are soft but do pull you up - eventually. The car has laid dormant for about 8yrs and has now been rebuilt - everything is new or refinished. I am running the same but now refreshed booster to the original modified master cylinder and same specs for the pedal and push rod to the booster. I've bled the brakes twice. There are no leaks in the system. All lines are double flared. I have yet to pull the drum covers off the rear to check the functionality of the slave cylinders and free them up if they need. I had the master cylinder off today to check the booster pin/rod - it is like it has been before and it worked perfectly fine. I adjusted the rod from the pedal to the booster to see what extra length I could get - not much - maybe 1/2 an inch. I'm doing another bleed this week, just because I think I need to. It can't be much - not sure what I am missing. The booster and mc are under floor mounted and fed by a remote twin reservoir in the engine bay. This is all the same set up as last time - only difference is soft brakes. Ive read blogs, asked mates for advice, dismantled it and reassembled it a couple of times - googled stuff on the interweb. It is bugging me no end. Anyone? Cheers.