ehall

A question of general curiosity based on his symptoms, could a warped rotor or rotors cause the same symptoms?

FRporscheman

If the squeek happens in pulses, or if the wheel's resistance to spinning pulsates, then it could be a warped rotor. However if the rotor is warped that much you would probably feel the car shake as you apply the brakes. This happened on the civic I had.

Try the wheel warmth test. It worked in diagnosing a bad caliper on a 560SEL we used to have. I rebuilt the caliper with an inexpensive kit and all was well.

Oddjob

I cant imagine ever warping a rear rotor on one of these cars.

What pads are you using?

If its a track compound pad, not uncommon for them to squeel even when coasting - right after letting off the brake. There is no spring that pushes the pad away from the rotor when you let off the brake pedal, so the surface of the pad still is touching the rotor (just not being pushed hard into it). If the car will roll when in neutral, it doesnt sound like you have a brake/caliper/e-brake hanging up to me.

You can pull the pads out and clean the caliper and make sure the pad guide/shim plates in the caliper are not messed up. Sometimes pad backing plates are a little too large (or the guides are mis-shaped) causing the pads to hang up a little (but usually a harmless problem).

Biggest flat bladed screw driver you can buy/find. I have also used pieces of oak trim/moulding (to be easier on the piston and rotor edges), but wood does not last long. It does take some effort to push the pistons back in, unless you open the bleeders and drain the fluid in the cylinders off to a catch can, as you push the pistons in.

pjburges

Autozone sells this nifty tool for depressing caliper pistons, kinda like a specialty C-clamp that is designed to fit around a caliper. Ive lost mine now, but I remember that it sure made that job easy.

ZPmadA

Couldn't find any problem with caliper or adjustment of e-brake. I think Oddjob got it. They are Ferado and Hawk. I can't remember which is in the front and rear, but they are track pads. Would it be a bad idea to put grease (copper grease?) in between the piston and pad to try to quiet them down? I saw this done to a 928 on youtube, but then someone commented on the video that grease shouldnt be used.

Also, any tips how to clean the caliper and what product to use? Other than that I should be good now. Thanks to everyone for the help.

redmund

I've seen copper grease on the back of pads done plenty of times. Shouldn't do anything horrible at all (but please somebody correct me if I'm wrong). I even saw it done on a UK show called Wheeler Dealers on Discovery Real Time, where this guy buys up old, slightly beaten up cars, usually from the 80s, then his mechanic restores them. They had a 928S on there once, needed a full brake rebuild, and the mechanic put copper grease on the backs of all the pads.

Jfrahm

On the back of the pad you use anti-squeal compound, which I think is a high temp silicone that glues the pad to the piston(s.)

ZPmadA

hah, thats the video clip i was refering to on youtube... wheeler dealer.. interesting show with that 928

redmund

Great little show that, love watching it. They've done a few Porsches on there, 4 lug 924, that 928, and a California spec 911 (can't remember exactly which type). I've seen them fix up mark 1 MR2s and Lancia Delta Integrales, along with some more mundane stuff. Picked up some handy little tips from it too.

Oddjob

You can try to put all sorts of stuff between the pad backing plates and the caliper pistons, but dont expect much success if using track pads. Often, one of the major trade offs for the higher performance pads, is loud squeeling. Some pads, especially the carbon/kevlar based pads (like the old Cool Carbon brand name) are absolutely terrible on the street - removing the pads altogether and letting the pistons hit the rotors would be quieter.

If it does bother you, you may want to buy a cheap street compound pad and swap them in - to see if that helps reduce the noise.

You can use cans of brake parts cleaner to clean up the calipers, or any other good organic solvent and tooth brush will work (paint thinner, laquer thinner, acetone, etc).