hydrolic144

iTrader: (2)

87 GTA with the 9-bolt disc rear end. My brakes actually do work, and extremely well, but they are just many years old and I'm looking for replacements. I read on here that the fronts will also work on the rear, but that didn't work.

Anyone have any suggestions on a good set of pads?

87zjeff

iTrader: (4)

my 87 iroc had the 9 bolt disc rear and the front pads were the same as the rear. only difference being i had to pry the clip off the pad that was used to hold it into the front caliper piston to use it on the rear solid caliper piston if the clip was already on the pad.

hydrolic144

iTrader: (2)

How did you get the rear caliper piston back in? I tried the c-clamp method but seemed it wasn't moving it at all.

87zjeff

iTrader: (4)

the rear caliper piston is threads into the caliper. it requires use of the e-brake to keep it adjusted. there is a tool you can get from most auto parts stores to use for threading it back in.

hrspwr

iTrader: (3)

+1. Did the same on mine. The piston does not compress in, you actually have to spin/thread it back into the caliper. Be careful not to rip the dust boot.

ILMODC

Wait, could I have damaged mine? I used a huge C clamp and i got em in a touch to slide back on.

Reason why I ask, is I broke the factory seal and now have a leak where the hose connnects to the bottome of the caliper. I keep hearing to use a crush washer and it will cure the leak. Now I'm wondering if I jacked up the caliper and its actually leaking at the piston and not the bolt as it appears?

So you are saying when you press the brake, the piston actually spins out instead of pushing out?

hydrolic144

iTrader: (2)

Wow! Did not know that. Good thing I didn't force it but I did notice that I had to spin it to line it back up with the old brake pad notch. The clips that hold the brake pad to the caliper, should I replace those?

hrspwr

iTrader: (3)

Inside the caliper there is a mechanism that self adjusts the caliper everytime the piston is moved out OR when the ebrake is applied. To get the piston back in, it has to be spun not pressed. I found it out the hard way as well. I tried to press the caliper in as well like any other caliper that I have seen, but it would not go. Out of curiosity, by hand, I spun the ebrake weight to apply the ebrake and saw the piston spin. I got out the chanel locks and spun the piston the opposite way and sure enough it went back in. But my problem was that the chanel locks grabbed the dust cover/boot and ripped it, so make sure you are careful when you do this. this is also why you had to spin it to line up the 'brake pad notch', it spun at one time....
Spin it, line it up put it on and your golden. If the clips are brittle and need to be replaced then yes. If they are in good shape, leave them.

You may be ok, but it depends on where the leak is....The copper crush washers(plural) should be used when tightening the line to the caliper. This will make sure that any imperfection(s) in the flex line and the caliper are corrected with the washer (same thing applies where any gasket is used...). You cannot reuse them either as they will leak if you do. Try that first IF you do not have them on the caliper now. When putting the line on it should go banjo bolt, crush washer, flex line, crush washer then caliper. The crush washers should be sandwiching the flex line. Like this (compliments of carcraft lol)

TreeFiddy

Yeah, don't use a c-clamp, you can damage the internal screw/bolt. I had never heard of this piston spinning thing either, until I did mine last year. Use this tool to make life easy:

http://www.summitracing.com/parts/OTC-4589/

I did not know this tool existed either at the time, so I made this:



Here is the internals of my caliper, note this is the recall-kit pistons. You can see that of you use a c-clamp to try retracting the piston, you are actually trying to crush it down the thread rather than spinning as is required.

brando54009

cant you just use one of those zinc coated brake caliper blocks from the parts store for like 5 bucks and push in while you turn it? thats how I've done most rear brake setups

TreeFiddy

Yep, linked to one above for about $10.

I made my little doohickey. Then went to the local parts shop and saw them hanging on a hook. Then I went

hydrolic144

iTrader: (2)

Awesome!! Saw that tool at AutoZone for $12. Great info!

Question though. When you turn the piston in, and line everything up. When it's time for the piston to compress again, and how it spins, how does it turn and keep the brake pad in place?

hrspwr

iTrader: (3)

When the brakes are depressed or the ebrake is pulled, the piston does not spin, it comes straight out. It is on a ratcheting mechanism that allows it to stay as you positioned it. This allows it to also keep the pad in place.
To compress the piston, it must be spun.

TreeFiddy

Moreso, the piston MUST NOT spin during normal brake operation, or the piston ratchet wear adjuster and handbrake screw actuator won't work properly.

The little nubbin on the pad that interlocks with the slot in the head of the piston, is essential to keep the piston from spinning, and keep the pad in place. Before I figured it all out, I managed to get the piston retracted, but the slot was mis-aligned. I nearly ground the nub off the pad myself just to get it in and be done with it.

Luckily (ironically) I managed to damage the piston seal in my initial ham-fisted piston retraction with locking pliers (painfully slow), which led to fully dismantling the caliper to replace it (tearing out hair). Upon appreciation of how the thing actually worked, it became apparent what a mistake grinding that off would have been.

batty113

Does anyone know where to get new brake pad clips for the rear brakes? I tried the parts stores and they don't know what I'm talking about.