one rear brake not working

[fred79]

I recently had my tires changed and while every thing waas off and the car was on the lift I started checking things. well I noticed that the drivers side rear brake hasn't been working for a while. the rust is heavy all over the rotor and there doesn't apear to be any marks like the brake has been engaging at all what could cause this.
so far I am thinking about replacing the calipers and putting a new set of rotors on but if it the proportioning valve then I need to fix that first.

 

[SHOZ123]

I would take the caliper off and see if it is the slider pins. If the car has a lot of miles on it, bite the bullet and get a new hose and a rebuilt caliper. Also make sure the e-brake cable is sliding freely and **** it.

 

[BlackOnBlackATX]

at only $30 you might as well change the caliper for peace of mind. doesnt take long at all and like i said, its cheap enough. mine were from Autozone, caliper with piston and new boot.