i have a 1990 firebird formula 350 my rear disk brakes wont stop the rear

[willy d]

tires i bleed it at least 75 time? i have bleed the brakes 75 times atleast in 2 weeks everyday and the rear wheels keep going i have the car in the air thats how i know that they dont stop only the rear fronts no problem and they are disk brakes i dont get it

 

[Richard S]

Your car is equipped with a device called a proportioning valve. It is located down stream from the master cyl. and usually has an electrical connector attached to it. If the brass shuttle valve has moved to off center you will have to recenter it in order to get brake pressure back to the rear brakes. Remove the electrical connector, it is plastic and has a pin in the center. look into the hole that you took the connector out of and you will see a V type shape in the middle of the rod at the bottom. This is the shuttle valve and it has to be centered, I usually use an awl but be careful it is brass and can easily be scratched. Once centered you will get fluid to the rear brakes.

 

[Mike B]

you bled the brakes and they still don't work. well what does the brake pedal feels like, does it feel spongy, when step on it does it stay or does it move down. if the front ones work, i'd you got a bad valve or something