Topic: Help with rear disc brakes!!

[mattblack84]

I always had what seemed like a low pedal with air in the lines with the stock discs, now its a really nice feel only thing I did was the kit.

[Angelo]

Right, it is definitely something with the caliper design. I suspect its a combination of the prop valve and the rear disc ratcheting calipers, the prop valve GM part number in the catalogs is very specific, one part number for 79-81 Firebirds. The one prop valve fits all the aftermarket sells I am sure is not exactly tuned how GM intended.

I will know soon if an adjustable prop valve and/or hydroboost makes the brakes behave better.