rear brake problem on 90 3.1

[Taz202]

I'm not sure what's going on with my rear brakes? I pulled the back wheels off and saw rust and scale built up on the rotors, but only on the outer half of the rotor. I new I had problems already and had asked a mechanic friend about it. He suggested the calipers where seized. I tried turning the rotors with the brakes applied and they seemed to be grabbing. Also if it is in fact the calipers can I take them apart easily and free them up or should I invest in new calipers?
Thanks in advance

[GMMerlin]

Originally Posted by Taz202

I'm not sure what's going on with my rear brakes? I pulled the back wheels off and saw rust and scale built up on the rotors, but only on the outer half of the rotor. I new I had problems already and had asked a mechanic friend about it. He suggested the calipers where seized. I tried turning the rotors with the brakes applied and they seemed to be grabbing. Also if it is in fact the calipers can I take them apart easily and free them up or should I invest in new calipers?
Thanks in advance

The slides are frozen. Not an uncommon problem on that body style vehicle.
The caliber is frozen in one position and the piston is only applying the inboard pad.
I would replace the calipers.

Side Note..there was a GM technical bulletin on this complaint with a set of special tools to remove the slides and hone the bore, but after 14 years it is doubtful that any GM dealers still have the complete set of tools to perform the repair

[JAL]

Originally Posted by Taz202

I'm not sure what's going on with my rear brakes? I pulled the back wheels off and saw rust and scale built up on the rotors, but only on the outer half of the rotor. I new I had problems already and had asked a mechanic friend about it. He suggested the calipers where seized. I tried turning the rotors with the brakes applied and they seemed to be grabbing. Also if it is in fact the calipers can I take them apart easily and free them up or should I invest in new calipers?
Thanks in advance

I've had the same problem, and I heard a rumor that setting the parking brake regularly (minimum of once a week) helps to prevent the rear calipers from locking up.

[newfslumina]

Yeah sitting the parking brake at least a cpl times a week will save u hundreds of dollars in breaks....My last car was a Buick Regal . I had the same problem and costed me 1200.00 can. to fix. Learned my lesson since then with my Lumina

[Taz202]

I appreciate the feedback, although I'm not sure I'll be using the parking brake any time soon. In the course of removing the first caliper I discovered that my emergancy brake pedal doesn't even work. The pedal still moves but the ratcheting mechanism must be broke.

[bottomtech]

Actually, GM was reimbursing people who had the same problems with their rear brakes a while ago. The caliper guide pins were originally stainless steel, which seized inside the calipers. Evantually the outer pad would fall out.
We still have all the tools to replace the pins, but you best bet would be aftermarket loaded calipers and new rotors, about $125 per side.
Applying the parking brake onlys adjusts the rear calipers. The parking brake lever rotates a screw threaded into the caliper piston, which will ratchet if there is too much clearance between the pad and rotor. This keeps the gap closed and the pedal high.