Took my 56 Oldsmobile Super 88 for a drive and noticed my brakes had a lot of fade. The pedel went to the floor with little to no stopping power. I replaced the wheel cylenders on all four sides along with the shoes and adjusted them. When I took the car out for a road test same issue. I bleed the lines a 2nd time and Had the same issue pedal went to the floor and car did not want to stop. Anyone know whats going on? THe oldsmobile had a power brake system like buick and cadillac.

 

Sounds like your master cylinder is dead. Usually the seal is dead and cannot pressurize the brake system like it should. Unfortunately I haven't been able to find a rebuild kit for it or a master cylinder only available... They only seem to come with the booster rebuilt which might not be a bad thing anyways. Now is a good time to contemplate retrofitting a dual master cylinder on the firewall or even adding disc brakes