964rh

Hi

I've got pagid blues and standard discs on my 1990 C4.

During normal road driving the brakes squeal like a pig, which I knew would happen but when the brakes have been used on a track I get a small squeak from the left front wheel. After a few hundred road miles this disapears until I do another trackday and its back again.

Before I take it in, anyone got any ideas what i could be?

The pads and discs where fitted from new, both have completed three track days and about 1500 road miles.

Thanks

Rob

ps - is there anything I can do about the road driving squeal with these pads?

Bill Wagner

Sounds to me like the pistons in the caliper are sticking a little. Next time it happens, try tapping on the brake pedal lightly a few times to see if it alters the squeaking sound.

964rh

Thanks Bill

As soon as you touch the brakes the squeaking disapears, and then comes back when the brakes are released.
If it is the pistons sticking, whats involved to rectify?

Rob

Christer

After quite a lot of miles on the Autobahn and other very high-speed roads my brakes now sound like they rumble when braking from high speed......I don't really get any vibration though and the brakes are as phenomenal as usual but I guess this might be brake pad deposit on the discs?

Sorry for hijack Rob H!

Euromagination

I just installed new pads and discs on my 964 last week, and mine have been squeaking terribly ever since, but only when you put "medium" pressure on them. ???

...If I apply the brakes really lightly or very heavily, there is NO squeaking or squealing. The squeaking only happens if I apply anywhere from 20%-50% of full pedal pressure, and ONLY when I'm going less than 50 mph. It's a very steady, non-pulsating squeal from what seems like all of the brakes.

My disc/pad combination is Zimmerman/Textar. When I put the new pads on, I applied a little bit of copper anti-seize to each of the backing plates. Not sure why I did that other than that's how I learned several years ago, and now that I'm thinking about it, maybe I should have just put the pads in without applying anything to the backing plates???

"WTF?" as Christer's avatar says.

-Harry

Jim Michaels

Harry: I'm not sure what an anti-seize application would do, but it is usually advised to apply a thin layer of a silicone compound called anti-squeal brake lube on the back of pads.

To prevent or reduce squeal it is also advised to wash and dry the rotors to remove whatever compound the previous pads left on the rotors (especially if it was a different make pad). Proper bed-in is also important in reducing brake squeal, and different pad manufacturers offer somewhat different bed-in advice.

kris

I've got the same combination and no squeal. Didn't use anything on the back, no mushrooms, no anti-squeal. Did you have to take some of the paint off the sides of the pads? Squeal always reminds me of the movie "Deliverance " with Burt Reynolds, that was the first time I ever heard that word.

KirkF

I switched to ceramic pads. No more squeal.

Kirk

Brian_77_3.6

I have Pagid Orange on my car right now and while the bite is unbelievable in a high speed stop the squeal at 50% or less pedal pressure sounds like a freight train coming to a stop. The occasional times I drive the 911 on the street you should see the looks I get from people when I apply the brakes. Turns heads for sure.

Bill Wagner

Robh:

Thats the classic symptom of the caliper sticking a little. What's happening is that when you take your foot off the brakes, the piston isn't retracting fully and the pedal makes slight contact with the rotor, hence the squeal. You should probably take it to a shop to get it checked out properly, but you might want to try squirting some brake cleaner that's safe for the piston area on the offending brake calipers.

FWIW, mine has done this every now and then, but it's always gone away, usually in a matter of minutes.

Other "squealers":

I replaced my pads with metal masters from Pelican parts. The PITA mushroom dampers are now completely gone. The metal masters have a damping material on the back of the pads. It has kind of a "crinkly" finish so even if I used the mushroom dampers, I doubt they'd ever seat properly. In any case, I put a coating of high temp brake grease on the back of the pads and along the metal edges where the pad metal contacts the caliper body (NOT on the pad material!!) My squealing is now, after about 5 months of driving, completely gone.

Brake squeal solutions on these cars almost always seems to be a "crap shoot."

964rh

Thanks Bill

Going in on Thursday for my mechanic to have a look at.
He thinks it may be a build up of dust in and around the caliper. I'll let you know.

Thanks for the help.

Rob