I rebuilt the master cylinder and all six wheel cylinders on mine, replaced every bit of line and hoses, bypassed the hydrovac until I rebuild or replace it. I had no problem bleeding with no use of power bleeder, just the old fashioned way. I have very good peddle and no leaks. 1957 2 ton
What type of "power brakes" are on your 1957 truck?
I see that an Air-Pak compressed-air/hydraulic brake unit used on 1956 trucks (it might have been an option). It was bled differently from earlier big trucks that had a hydro-vac "booster".
