how do the rear brakes adjust?

[dmorlow]

Ok, I am starting to wonder this. Yesterday I had to put my parking brake on because I had to work on my car out of park. When I released my parking brake, my parking brake was stuck on. So then I had to lift my car and bang off the parking brake off. My last car was an 89 Cutlass Supreme. It's back brakes were nutorius for going bad constantly. But on that car, you had to use the parking brake regularly to adjust the back brakes in to compensate for the rotor getting thinner. Is this still true on my 95 Aurora? I have heard that GM has come a long way from the 89 to the 95 disc brakes. I thought some cars just adjusted the brakes when you put the car in reverse. But if I do have to put my parking brake on regularly, then I am going to have to fix my parking brake. Right now I am just figuring I will never turn it on again. But I saw in another post that someone was hinting that you had to use it to keep it adjusted.

[beachlover333]

It doesn't adjust since it's either on or off. Mine did the same thing, so I just don't use. I tried lubricating for days and could never get it to release properly.

[dsatt12]

I give mine a few good stops in reverse to set mine.

The parking brake sticking should have more to with rust/dirt in the cable system more than the rear caliper.

[Spinman]

The shop manual states that use of the parking brake does adjust the rear calipers (for a 1996). That said, it would not explain why yours was stuck. As stated, I would check for rust and dirt on the cable.

[dred98]

Originally Posted by Spinman

The shop manual states that use of the parking brake does adjust the rear calipers (for a 1996).

I've owned my car for about 8 months and have never used the parking brake - maybe I should start, just to adjust the brakes!

[RobertHammen]

I used to have a '91 Grand Prix, one of the infamous early W-bodies whose rear calipers seized open quite frequently. The common recommendation was to ALWAYS use one's parking brake - something I've done out of habit on all of my cars since (including my Aurora)...

[ugsrich]

The same way the front brakes adjust - continuously as you apply pedal pressure.

Drum brakes have a self-adjusting system that engages when braking in reverse as suggested. Disc brakes however are continuously “adjusting” to pad or disc wear.

As the pads wear down the brake piston moves out to accommodate the reduction in pad thickness. The piston only relaxes when the driver releases brake pressure at the pedal but the piston is not retracted per se. (The case with spring retracted drum brake shoes required adjusting to accomodate for wear.)

In addition to the piston extending to accommodate wear, the caliper floats on the two mounting pins. This allows the caliper to float ensures that equal pressure is applied to both the inboard and outboard pad. These pins are tightened to the caliper but actuallyfloat on o-ring bushings inside the caliper mount. When the pads are replaced the pins should be lubricated with some silicon grease to ensure that they will allow the caliper to adjust its position in harmony with the pad wear and the piston.

It may be that you have a sticky parking brake cable as described in a previous note. I do not have access to my service manual, but I believe that any adjusting that is going on has to do with the parking brake actuation only…to accommodate the cable’s stretching over time as well as the change in pad thickness from wear. I’ll check it out later in the week.

[jjdewd]

By working the parking brake.

I recently did a brake job ...pads and rotors all the way around.

On my "96" the rear caliper piston isn't floating quite like the front. If it is, its limited it to the movement of the caliper. It screws in and out. The parking brake ajusts it out as needed, and when you change the pads you have to screw it back in ...not compress like the front.

Clean/lube/free up the cable and use it every so often to adjust and it won't freeze on you. I just give it a few pumps ever now and then. You can feel the difference in the brakes after.