I have read taht the back disc brakes are adjusted by the emergency brake when you use it. is this true, because my e. brake doesn't work and I'm not happy with the braking of my car, so I was think that may be it. any help would be greatly appreciated!

Josh

 

You can adjust the grip at the back by popping off the little rubber tab on the inside side of the brake assembly, and turning the little dial with a small screwdriver, do small adjustments at a time though, as it pushes the shoes outwards, but locks when you try to come back in, it's a PITA to back off the shoes without taking off the drums,because of a little spring locking tab on the outside-side of the assembly.

Also if you make a series of starts and stops in reverse, it adjusts the balance of the back brakes side to side. Not quite sure how this works, my dad explained it to me a while back.. Has to do with the shoes rotating when you apply them in reverse, and allowing the adjustment dial to expand. again, i don't remember exactly how or why, but that's how it works.

I'm not sure if the second method will tighten things up, or just balance side to side, maybe someone else can help us with that bit.

 

He did mention that he had disc brakes. AFAIK, only the newer style disc rears are self-adjusting, though. On an 87, you'd have to get dirty and do it yourself.

 

thanks JZA I just didn't think that all disc brakes should brake THAT bad. :-) I'll do that first thing when I get a chance. the front brakes do adjust themselves though right?

 

Yep, the rears are adjusted by the e-brake. However, GM used the wrong spring inside the actuators (pistons), and the brakes were recalled for manual transmission'd cars, and a technical service bulletin was issued for automatic transmission'd cars.

I just brought "back to the top" the message on how exactly I fixed my '84 rear discs. Here's the quick link: https://www.thirdgen.org/techbb2/sho...threadid=78725

And yeah, front brakes adjust themselves. The adjustment is really the position of the piston, and where the caliper is located along the caliper mounting bolts. By pressing on the pedal, the piston pushes outward. When the piston meets resistance, it starts sliding the caliper along the mounting bolts. When the caliper stops moving (outer brake pad meets rotor), that's when the caliper actually squeezes the rotor. When you release the pedal, the piston only backs off a bit.

On a malfunctioning 82-88 rear disc caliper, the piston retracts all the way, but the caliper stays in its position along the mounting bolts. So, when you push the pedal, the piston extends outward into "air". When the pedal's down, the piston isn't pushing the inner pad out to meet the rotor. Try this (because I'm curious)- double pump the brakes when you're on a road by yourself. When my rear disc brakes were just "pretty" (and not working), if I pressed the brake pedal down, released it, and pushed down again QUICKLY, my rear brakes would work. Seems that by doing this, the rear pistons weren't able to retract fast enough- and they'd stay where they should. The second pump of the pedal was able to push the piston out so the inner pad would meet the rotor.

If you go thru the pain of rebuilding the rear discs (covered in the Haynes 82-92 Firebird manual at Pep Boys for $15, in case you don' t have the $80 GM book), you should also replace the rear brake hoses. Since you'll have the caliper off, you should probably replace the rusted-up caliper mounting bolts (Bendix #H5014, each, $8). Since you replace the bolts, you should also replace the "bushings and slides"- this is the hardware on the caliper that "slides" along the mounting bolts- and Bendix kit #H5611 contains the slides & bushings for both calipers, for $7.

If you want to start fresh, you could turn in your old calipers for rebuilt ones- but they'll still probably have the incorrect pistons. I did that for one of my rear calipers, and it had the same problem as the factory one. My factory one was too corroded (internally) to rebuild.

And if you go thru all that, do yourself a favor and shoot the calipers with some paint.. I used cast-iron-gray, but there's other paint out there (engine paint, and http://www.eastwoodcompany.com sells actual caliper paint).

Any questions, let me know!

 

I knew that, i was just playin....

 

does anyone know if the e brake cable setup is the same setup no matter if it is a rear disk or rear drum, man or automatic. I have rear disk automatic tranny and really need the entire setup. the previous owner took it all off for whatever reason. I need it to be able to adjust my rear brakes.