Looking for recommendations , don't need the best but don't want to buy junk. thanks

The biggest challenge will be loosening steel bleeders which have corroded/seized inside of aluminum calipers. One of my most feared maintenance duties.

I thought they were cast iron on a 86?

I believe that all Fiero calipers were aluminum from the factory... but it's pretty easy to determine with a magnet.

On an 84-87 Fiero, if you have a cast iron caliper, it's probably because a previous owner did the Grand Am brake modification.

For bleeders, you can try heat+WD-40 and then turn the bleeder with a pure twisting motion, without side load on the bleeder.

Also, you can try an impact gun. The sharp impacts do a better job of loosening parts without breaking them, versus brute muscle power.

I use an air impact wrench, with the trigger held partway, but that's just because it's the impact I bought when I was 16 years old.

Today there are smaller electric impact guns that might be more suited to this type of work.

Thanks guys, if they won’t break lose will i have to get new calipers?

If you don't twist so hard that you break off the bleeder, you can bring the caliper into a garage (or machine/repair shop) that is used to dealing with this sort of problem.

If you do twist off the bleeder, that's not a bad thing. Experience helps with removing bleeders; breaking some off is a good way to gain that experience. I've broken at least one or two.

If the bleeder has been twisted off, you can replace the caliper with a rebuilt one (use your original as the core, even if the bleeder is broken off). Otherwise, you can see if the machine shop can help you. They may be able to weld a nut onto the broken-off stub inside the hole, and then be able to get a grip on the stub with a socket wrench.

For brake bleeders, only use 6-point deep sockets!

I believe the wrench size is 10mm or 11MM depending on the bleeders you use. Do use the recommended 6 pt box wrench. Don't put full wrist power into the bleeder screw or it will break off. If it doesn't back off relatively easy then try rocking the wrench a bit, a little tighter then a bit looser. If it doesn't come loose then head out to a machine shop.

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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 "

Got it... but now thinking since they are original OEM maybe I should replace them with rebuilt , and do the flex lines while I’m at it.

The car did sit in storage since 1991, the breaks are ok but not great, a little soft..

Opinions and advice please.

I am not a proponent of the break caliper swap but it seems to be getting harder and harder to purchase stock Fiero calipers. Has anyone tried looking at Wilwood calipers for a direct substitute?

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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 "

What do you mean by swap? With non gm part?

In answer to your question, I use a Mityvac MV8000 vacuum pump. It comes in a kit with all the fittings a you need to vacuum bleed your brakes. As Patrick said, the biggest challenge will be loosening steel bleeders which have corroded/seized inside of aluminum calipers. When you get the old bleed nipples out, you may want to replace them with speed bleeders. They make brake bleeding a 1-person job.

Thanks I will check them both out..

I used the cheap green vacuum bleeder available at Autozone on the Fiero and it worked perfect. It has survived being used to bleed the brakes on three cars so far so I'd say it was well worth whatever I paid.

quote Originally posted by hunter29: Got it... but now thinking since they are original OEM maybe I should replace them with rebuilt , and do the flex lines while I’m at it. The car did sit in storage since 1991, the breaks are ok but not great, a little soft.. Opinions and advice please.

Personally never have been able to get a rebuilt caliper that worked well. I had one rear caliper I swapped out and I got a lifetime warranty on and it kept leaking and failing every year or so. The other three calipers never failed while that one kept going out. I now have enough OEM calipers to last a lifetime even with 3 88's. I bought like 5 sets of NOS fronts from calipersonline a decade ago and have a couple sets of used spare rears. I would never want to get auto store rebuilt caliper again.

I did have one bleeder break off on an 88 rear and was able to weld a nut on and get it off finally. There's a thread somewhere in the archives from that ordeal.

[This message has been edited by reinhart (edited 03-24-2021).]

Are the '84-'87 Fiero calipers unique to the Fiero, or do other GM cars use them also? I'd always assumed the latter but cross-referencing the part numbers on Rock Auto just now they don't list any other cars using those parts.

As for brake bleeding: I've always gravity-bled my Fiero. It's an '88 but I don't think that matters. For the rears, I lower the rear end of the car so its about an inch above the ground just to give the downhill flow a little more motivation.

Thanks guys, looking around and not finding OEM calipers. Thinking of keeping mine and replaceing with after market, but what brand and can i get them new ?

I haven’t Done a brake job in years so I’m learning again..

I've got the one way bleeder screws on all 4 corners on my "85 GT. They make bleeding brakes a breeze.

Gravity bleeding does work most times. May take a very long time if you replace long hard lines.

To make fluid go thru tubes on bleeder "screws..."
Take bleeders out and lube threads w/ Brake Grease. That act as sealer and lube later when done.
Any scrap hose can work but if can get them, O2 hoses from hospital etc works very well. One end has a plastic "fitting" that hold most size of bleeders on cars and trucks.

If you vacuum bleed then lubing bleeder is often required or too much air goes thru the threads.

Note: Vacuum bleed "kits" often break before used again for most DIY. Also Vac Hand pumps, even best ones from MityVac, can get wrecked when sucks in brake fluid, oil, etc.
So don't spend a lot on them.

Pumping the pedal has problem, most so if MC has problem.

See my Cave, Brake Service

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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