1983 Trans Am rear disc brakes.

43k miles on the clock, sat most of its life: Worn pads all the way around, worn rotors, semi frozen calipers on the back, bad master cylinder.

I changed the rotors, pads and calipers, and master cylinder. Upon road testing I found that the pedal was very spongy, just as before the fix - but not only that the car would barely stop. I re-bled out the system, and found improvement, but upon working the pedal the master cylinder would bubble up air when pumping in the rear chamber. I backed the car onto ramps to level the master cylinder and bled it on the car, I know that really isn't by the book, but it worked to remove air that was trapped in it (clearly my fault). Road tested and found improvement, but still not the quality of braking that the car should have. I removed the front wheels, and calipers and found the front brake pads prematurely cracked and chipping away. I replaced with ceramic pads, reassembled and road tested and found normal operation of the brakes within about 5 miles of seating the brakes. Since I used the same brand of brakes that prematurely failed on the front, I will remove and replace the rear pads (possibly not needed), but I can't trust pads that cracked and failed within a few miles.