i have a 1991 trans am gta, when i press the brake pedal the front brakes dont release when i let go the back do. The calipers are working good. What can it be? thanks in advanced i need this car running good! thanks

Sounds like the master cylinder. I had same problem on my vette and it was the master.

more likely than not it's the front rubber flex lines . old ones can/will collapse internally , then act as check valves . it's common with older vechicles , i have had it happen to myself several times . it's not only G.M. vechicles , i had it happen to my 1989 dodge p/u . i have owned my truck since new . many others on this site will confirm . replace them , good luck .

"Collapse" isn't exactly what they do, but the effect is about the same... they rust internally, and eventually completely close off the little tiny hole through the fitting.

Just change em out, and then go from there.