How Hard is it to Rebuild the Fiero Rear Brake Calipers? (Page 1/2)
RotrexFiero DEC 25, 01:06 PM
Everything is there in the headline
Gall757 DEC 25, 01:20 PM
Well, I'd say on a scale of 100 it's about a 99. If you are not yet a certified mechanic, maybe you should not try.

Our resident expert, The Ogre, has written extensively on what is required......go to the Ogre's Cave and read lots of his advice.....and he should be along to to comment on your post shortly...... Merry Christmas!!
RotrexFiero DEC 25, 03:20 PM
Well, that could be said for the whole car. I am certainly not a certified mechanic, but I've pulled, rebuilt, and installed engines and such.

The reason I ask, from what I've noticed, parts have become rare for these cars. Especially the ones that are specific.
Dennis LaGrua DEC 25, 03:56 PM

quote
Originally posted by RotrexFiero:

Well, that could be said for the whole car. I am certainly not a certified mechanic, but I've pulled, rebuilt, and installed engines and such.

The reason I ask, from what I've noticed, parts have become rare for these cars. Especially the ones that are specific.


Those calipers are rebuildable, and that is if you can get the pistons out without scoring the bore. Then you must locate the pistons and seals that may be hard to find. The old pistons are often broken from previous mechanics trying to use a brake pad compressor on them.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

RotrexFiero DEC 25, 08:38 PM
I ordered two new one, but I am wondering if I should hang on to these old guys (the old calipers). They are getting rare.

Maybe I'll try to rebuild them in my spare time.
Dennis LaGrua DEC 25, 10:51 PM

quote
Originally posted by RotrexFiero:

I ordered two new one, but I am wondering if I should hang on to these old guys (the old calipers). They are getting rare.

Maybe I'll try to rebuild them in my spare time.



Try to find the exploded diagram of the rear caliper that will show how all the parts fit together. I would always hold onto the cores.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

theogre DEC 25, 11:01 PM
"How Hard is it to Rebuild the Fiero Rear Brake Calipers?"

"Rebuilding" by installing Seal Kits often has problems more so w/ aluminum shells. (Yes, Highlights in cave.)
Like Many think can "hone the bores" to use them but cause more headaches w/ aluminum shells. If they "hone them" then wreck them using wrong grit and more. Even "Cast Iron" shells don't need honing because bore does not touch the pistons. (Honing is often needed w/ iron slave cylinder bores in Drum Brakes because how they work.)

Many Al shells are too damage to fix by DIY and most "pros." But try anyway then blame the OEMs for brake problems.

So Seal kits can work IF some shell areas are very good. For rears, there are 2 critical areas.... Main "o-ring" groove and hole where P-brake screw goes thru. "Rust" or other damage then they often fails now or very soon. Also many Main o-ring groove isn't square but more like \_| with \ toward the pad to allow the ring to move when apply and act as a spring better.

Even w/ new pistons and seal kit, often installing can be harder then claimed. Especially P-brake screw likes to tear the o-ring going into the hole and leak now or very soon. Worse this leak is often not obvious until total fail and have sinking pedal at red light etc. Meanwhile Leaking fluid can attack alloy wheels.

Worse, Many also think can take apart "Fiero type" rear pistons to make them work. Often work for awhile then have low pedal to brake fail or wheel fire because F'ed rear piston drag the pads.

As is Many pistons have "blown out" backs for failing to self-adjust but use the clamp to retract and force the back down and hind the problem.
With a good clamp and done right, the clamp needs very little effort to retract the piston. Finger force or less. More then very likely have major problem w/ blown apart piston. Example:


Plus Seal Kits don't have slider "o-rings" and often need them. More so when someone use anything but Brake Grease in the slider holes.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

wftb DEC 25, 11:02 PM
The problem with the rear calipers is that they have an extra seal inside the piston that is part of the parking brake. Most rebuilders just ignore this seal and you buy a rebuilt caliper and then it usually leaks. There are threads on here that describe how to take apart the rear caliper piston.

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86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

theogre DEC 25, 11:15 PM

quote
Originally posted by RotrexFiero:

I ordered two new one, but I am wondering if I should hang on to these old guys (the old calipers). They are getting rare.

Maybe I'll try to rebuild them in my spare time.

Keep old ones and seal kits and new piston if you find them but Do Not install.
installing then storing often won't work month to years later.

That even when the piston is good etc.

Unless you take apart and let old fluid drain/dry then the fluid pulls water from air and "rust" everything.
If the old pistons are good now, may not be after months of storage.
pmbrunelle DEC 26, 01:25 AM

quote
Originally posted by theogre:
Unless you take apart and let old fluid drain/dry then the fluid pulls water from air and "rust" everything.
If the old pistons are good now, may not be after months of storage.



Do you think it is good practice to store pistons in closed Mason jars?

Anyone with a welding setup could also fill the jar with welding gas before closing the lid. Argon is heavier than air, so it will stay down before the lid is screwed on.