I have a problem with the rear brakes on my '89 IROC....They do not stop very well if at all. While on stands I can put the car in gear and the ear brakes will not hold the wheels from spinning. If I put my foot on the pedal real hard they almost stop. When I put the e-brake on they will hold. I have already done new rear S/S braided lines, and they bled out real good. Flushed all the fluid and replaced with synthetic. E-brake is adjusted tight enough I think. When pulling up the e-brake handle it comes up about 7"-8". Any help would be great.
They are rear disk. They are the PBR ones. Also no fluid leaking from any where. I checked that at least 3 or more times. Losing no fluid from anywhere??
The pedal is not mushy at all.
What gives I have a thread started on Camaroz28 I got a little feedback on it but I would like some more. Any help would be greatly appreciated.

 

I'm thinking the most likely thing needed would be a caliper rebuild. Second thing I would look at would be the bias valve.

 

Sounds like siezed caliper or calipers to me. Exchange calipers are relativly in expensive. I would go ahead and replace them for safety sake.

 

like Andy was talking about, check to see if your piston is not bottomed out and stuck within the caliper.
Pull your pads and look for uneven thickness between one end and the other. It should be even wear across the entire surface.


BTW - nice lookin ride

 

I have pulled the wheels off and check to see if the pistons are cocked in their bores and they do not seem to be. Also the pads are wearing evenly(all 4). On Camaroz28.com most of the responses are making it to be a hydraulic problem?? I just do not want to throw parts on it. While on stands they will slow down put to stop you have push the pedal that "little extra bit" harder than normal.

 

Then remove the brake pads. push the pistons all the way into their bores until they bottom out. Carefully observe the amount of pressure it takes to move the pistons. This alone will eliminate the "siezed piston" possibility.

If that is ok then you must install a pressure guage on the caliper to check the pressure front vs rear.

 

cool thanks....Where can I get a pressure gauge from for my needs?

 

saw an article on another site about this. the person said to remove the spring and plunger out of the proportioning valve. this will allow more pressure to the rear. i did it and now my rear brakes work great. to remove these parts you need to remove the nut on the front of the valve. then pull out the spring and plunger. now, the nut as a hole in the middle. you need to plug it. i put a self tapping screw to seal it. a 3/8 pipe plug does not fit.

 

i have heard the same thing about removing the spring and plunger. I only removed the spring however, as i wasnt sure how to plug the hole. This did not seem to help the situation at all, but i would like to remove the plunger also. What im worried about is plugging the hole, and a screw just doesnt make me feel good.

Hopefully i can figure something out, as im pretty sick of this 4 wheel disk conversion, its been nothing but headaches since the start.


Good luck with yours

 

Sorry to hear your problem......I heard the same thing about the removing the screw and plunger also, just wanted to see if any one else had done it???
Merry Christmas to all!!