HeavyThundar

Anyone ever made a thread on rear caliper teardown? If not, i tore one down tonight and took some pictures and a couple of video shots. Would be happy to share.

Say yay or nay.

Z28Smitty

That would be great. I have a 90 Iroc rear end w/disc brakes and 3.23 gears that I'm planning to install in my 92 Z28. I'm in the process of tearing down the calipers now so I can bead blast and them powder coat them red to match the fronts.
It's not going so well right now... I'm having a tough time removing the bleeder screw on one side and the parking brake lever on the other side is broken.
I'll be looking for the brake lever this Saturday at GM Sport Salvage.

JamesC

iTrader: (5)

Your 90 should be equipped with PBR's, which are completely different than the OP's (I assume his are the old-style Delco-Moraines). The lever is available from the following site:

http://www.flynbye.com/

JamesC

HeavyThundar

Ok, guys and gals. I'll probably have to revise this later to add in some things.

Here's what i'm working with, a dirty 87' Iroc with two frozen rear calipers.

Fig. 1


Heres a couple shots of the brake caliper. These are the older style calipers, i believe i read they changed to a new design in 89.

Fig. 2


Fig. 3


Fig. 4


Vid. 1

Here's a video of an improperly working Park Brake caliper. You can see that everytime the parking brake is released, the piston turns, screws out, and does not retract. This is due to binding/frozen inner piston. The piston will continue to extract until it has pressure applied to the pads and rotors and locks itself down.

After you get the caliper off of the vehicle, if you wish to disassemble:
1.) First allow as much brake fluid as possible to drain out of the caliper.

2.) Grab a handful of rags to keep near by, and try your best to keep brake fluid off your hands and any paint that you don't want to ruin.

3.) Place a rag on your work area under the caliper to catch any fluid.

4.)The easiest way to remove the caliper piston, is with compressed air and a rubber tipped air blower. CAUTION!! Before you go any further, place a rag inside the caliper as to cushion the piston from being damaged when it is blown out. Head my warning, the slightest knick/bur/damage to the piston will cause you trouble down the road.

5.)CAUTION!! Make sure your hands/fingers are not in the way of the piston, as it will be ejected at high speed via compressed air and spring pressure. Place the tip of the air blower in the brake line inlet, and apply pressure. It wont take very much pressure if the piston isnt frozen to the bore, just a quick shot and it will rush out.

6.)When the piston is blown out, 2 springs will be ejected, along with:
-a spring seat
-a shim
-a torrington bearing
-an internally threaded gear that works the park brake feature
-and dependent upon if the park brake feature of your caliper was frozen up or not, the inner gear driven piston. If your PB was frozen up, the inner piston may be seized inside the caliper piston causing the problem. Refer to step 7 if your inner piston is frozen inside the caliper piston, skip to step 8 if otherwise.

7.)Try tapping the bottom of the piston in a straight downward motion on your work bench to free the inner piston. If no luck, remove the rubber plug to expose hole in the caliper piston (Fig. 5). Spray some PB Blaster/Liquid Wrench/WD40, or whatever other monkey **** you use in the hole and allow some time to soak in. Use a small roll punch and tap on the inner piston to break it free, trying to tap as light as possible.

Fig. 5


8.) After the piston is removed, use a screwdriver to remove the outer piston seal, and the inner platic/teflon bore seal. CAUTION!! Be careful as to not scrape/knick/damage the piston bore when removing seals.

Fig. 6

This image shows the piston seals, piston, inner piston, threaded gear, torrington, shim, spring seat, and the other spring in clockwise order.

9.)Clean caliper housing, pistons, and other parts in parts washer. Use a scotch brite pad in the parts washer to scrub away rust/grease/grit.

10.)Inspect pistons for knicks/burs/pitting or any other damage. If there's the slightest amount of damage, trash it. The smallest burr will eventually cut through the seals and cause leaks.

11.)Inspect piston bore (as seen in Fig. 7) for the same clues. Hone cylinder bore if damage is not critical.

Fig. 7


12.) If your parts look ok, buy a Brake Caliper Piston Repair Kit from your trusty parts dealer. If your not so lucky, you'll have to buy a new caliper.

JamesC

iTrader: (5)

The following site sells the 'fix' (recall) kit:

http://www.flynbye.com/catalog/i208.html

JamesC

HeavyThundar

Ok, heres my question. These calipers were put on last year, they're replacement units from Car-Quest. Would they already have that recall kit in them or not? I can't see the picture too well as to tell what the recall kit supplies differently, does anyone know?

JamesC

iTrader: (5)

The calipers I put on several years did. Check the following for specs:

http://members.shaw.ca/crussel/recalls/86c28/86c28.html

JamesC

HeavyThundar

That claims 82'-86' camaros, mine is a 87.

JamesC

iTrader: (5)

As long as they're the old style Delco-Moraine's, I doubt it matters. Note that flynbye advertises 83-88 (88 being the end of that caliper type).

JamesC

HeavyThundar

Honestly, id like to go to a different caliper. I've spent way too much time messing with the rear brakes on this car, i just need a good reliable caliper, i dont care about the park brake working or not.

JamesC

iTrader: (5)

Here's one option, the 89+ PBR's:

https://www.thirdgen.org/forums/faq-...iscs-89-a.html

JamesC

kiss4afrog

If these are from CarQuest, shouldn't they have a lifetime warranty?
Good writeup on the overhaul.

Benett

Do you know where I could find one of those rear caliper e brake return springs?