My rear calipers on my 90 bird are either seized up or are getting minimal pressure. I replace all the brake fluid and bled the brake lines. That helped a little considering that the old fluid had the consistancy of pancake syrup. I called around and the cheapes price I could get for new calipers was $89.00 for the set. This is a bit steep right now for me. My question is , how can I service them. Do they just need the sliders lubed, or do they need a complete rebuild? If they need a rebuilt, where can I get the kit and how difficult is it. I also heard that when compressing the calipers, you must twist the pistons. Can someone please help me out here, I need to get this car inspected.

 

Unless I'm waay out to lunch, the year 90 model pistons do not screw in, only those pistons on rears prior to 89 did, so that's not a problem. If you can't afford to replace the calipers, get a rebuild kit from a parts store or the dealer. The GM seal kit part number is 10112655 (89-91 rears). They aren't too steep. Might as well rebuild them completely while you're in there. I've seen a caliper rebuild but I haven't done one myself yet, but it looks easy enough. You need a compressed air source and basic hand tools. Remove the calipers and the brake line. Place an air nozzle in the brake line hole and "blow" the piston out of the bore. Remove the dust boot and the piston seal (remember how it all comes apart), and clean the caliper housing very well... make sure it's real clean. Dip the new seal in NEW fluid and place it in the groove in the caliper. Dip the piston in NEW fluid, reinstall the piston carefully, and then the dust boot, and whatever new seals, etc, they give you. Then put the caliper back on the rear and bleed the system. I would also replace the hoses while you're at it, they may be clogged as well. (Gotta love Shadetree Mechanic!!) Hope this helps a bit..

 

Yep, a caliper rebuild is cake. A "real" auto parts store (not Strauss or Pep Boys or etc) will be able to get them for you. I ordered mine through http://www.wrenchhead.com ; http://www.carparts.com also carries them. You might not even need compressed air to pop the piston out of the bore; when I rebuilt my rear calipers (off an '84), I just wiggled the pistons a bit and they popped out. I'd imagine you could use a bicycle pump; I don't think you need a "shop" air compressor.

Oh yeah; the kit cost me $12. I also purchased, out of carparts.com, new caliper mounting bolts, and a bendix "caliper hardware kit" which came with the slides & rubber bushings. And yes; caliper mounting bolts are that expensive- like, $8-$10 a bolt! I thought I was being scammed until I checked a few places...

The $15 Haynes 82-92 Firebird manual gives a pic-by-pic rebuild of both style of rear calipers, and they're excellent directions. The ones for my 82-88 rear calipers matched the same pictures in my '86 GM Service Manual. But otherwise, ebmiller88's right. You're removing the old seals, cleaning the hardware, lubing the new seals, and putting it back together. If you were in a hurry, 10 minutes at the bench is probably all you'd need. I took my time- and even painted the calipers with a cast-iron-gray paint, and painted the brackets with black rustoleum. I had to do it!



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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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