Ed Burdell

Morning, everyone:

Last weekend, I changed my front brake pads. First time I had done the fronts myself. No big deal, except that I was expecting to fish out and remove those round, anti-squeal spiders (aka pucks) that we all know and despise. Instead, I found thin, flexisble metal plates with shiny metal cylinders attached to them, aligned so that the cylinders line up with the pistons. After separating the old pads from these plates, I couldn't get the plate assembly itself out, so I left them there and just slipped in the new pads and went along my merry way. The new pads worked like a champ.

Fast forward three days later, and now there is this horrible screeching sound when I'm driving - not merely when I apply the brakes. Tremendous loss of cachet and the fear I messed something up. Perhaps it's merely the pads vibrating against those metal plates - I didn't use any adhesive. Or perhaps there's something more sinister.

My questions to the group:

1) Has anyone encountered this type of spider/puck before? I was quite surprised when I saw it. Two solid (or solid looking) aluminum cylinders attached by a screw/rivet/weld/something to a flexible aluminum plate, rectangular. The assembly is impossible to remove without removing the caliper from the rotor.

2) Perhaps the sound I'm hearing are the pads resting and rubbing on the rotor as I drive, even without the brakes being applied?

3) Finally, what keeps the pads away from the rotor face when the brake pistons retract after braking, anyway? I mean, we're just slipping them in there and keeping them in place with that retaining clip. Why don't they rub the rotors all the time?

Thanks in advance.

911PERVY

They sound like 996 or 987 versions;

johnsjmc

The caliper piston seal is responsible for the retraction of the pistons. It distends on application and relaxs back to it,s rest position when you release the pedal. Very little movement away at all. I don,t use any anti sqeal spiders or anything else and so far have quiet brakes. Standard 993 C2 with cheap metal master pads, street driven only.

Ed Burdell

That's the beast. Since I've owned the car, I've had the pads changed out by others twice and now once by myself. Wonder if they had them when I bought the car...or if my brake mechanic made the switch.

Either way, am I correct in assuming they're meant to be reused? Otherwise, it would force you to yank the caliper to change them.

Do you think applying adhesive to the pad would make this dreadful noise go away, or do I have an unrelated problem?

911PERVY

They arent meant to re-used but can be, yes, doubled sided tape or contact adhesive should work as long as all surfaces are nice and clean. Looks like you have 944 ones fitted. Yes, they can be a bugger to change, just ask the 996 or Boxster boys!!

bart1

Which is why when I bought my Pagids for the track, I removed the factory pads' spiders so I can switch them easily. I do get squealing with the factory pads sometimes (only when light braking) and most definitely with the Pagids.

Ed Burdell

Yes, I removed the 993-style spiders from the rears (and they're quiet enough without them), but I can't get these 996-types out from the fronts without pulling the calipers, something I'm not willing to do until the rotors need replacing.

H.H.Chinn

When I did my brakes with MikeJ a couple of months ago, we used the spiders that I bought along with the OEM pads from Sunset Porsche. They have an adhesive that adheres to the back of the brake pad aligning the assembly perfectly inside the caliper with the pistons. The factory pad spiders are serrated (slotted baskets) and applied when they were manufactured. We surmise that this allowed the guys on the factory line to just slap them into the caliper in perfect alignment without having to peel and stick the solid pucks for the pad's alignment. I also installed new wear sensors just for peace of mind, since the original factory ones seemed to fall apart and not stay together once reinstalled.

Oh, BTW No squeal!!

ande5000

I don't understand what the big deal is about the stock vibration dampers. I've found they are easy enough to separate from the pad backing plate, and can be reused just fine. And they do work well to eliminate brake pad squeal, especially with high performance or racing pads, which we all find really annoying. I run them with Porterfield R4 full race pads and....no squeal.

To separate, just take a thin blade putty knife or paint scraper and work the blade in between the damper and the pad backing, moving the scraper side to side as you apply downward pressure. This can be done at an angle if necessary to give you a better angle at controlling the scraper as you work it down between damper and pad. After a minute or two of this action, eh scraper will cleanly separate the damper from the pad, which can then be easily removed.

Then, just reuse the damper (assuming it's not torn or badly frayed). If they're old, the spiders won't have much spring in them and they fall out easily, but if they're fairly new they should hold in the pistons without falling out. After even one separation the adhesive backing will more or less wear off, or get less sticky, but this just makes it easier to subsequently remove the pads (I still have to use the scraper, it just gets a lot easier).

After three DEs this season, with pad swaps before/after each one, I'm still using the same stock vibration dampers with no issues.

Ed Burdell

Yes, we know all this. The 993 spiders are a joy to remove or a pleasure to keep and re-use.

The question is dealing with these 996 parts that someone saw fit to inflict upon my poor 993. Is it the consensus here that I pull the new pads, spray adhesive on the back, and then reinstall, or should I pull the calipers to fetch them out? Or will spraying some "Squeak B Gone" get it done? Or does anyone have a way of getting them out without pulling the calipers? Again, we are talking about the 996 anti-squeal parts, not the 993 spiders. Thanks.

black ice

What kind of pads are you using? I used two different brands of aftermarket with NEW spiders and had the most ridiculous embarrassing squealing you've ever heard. Took a month or so of bedding in OEM pads before it went away.


dave

Ed Burdell

Just pagid blues...the squeal I'm getting is different from any squeals I've heard before. The main concern is that it squeals even when I'm not braking.

TrackDays247.com

I've seen *4* different variations - amazing.

MDamen

Sounds like the pads are not retracting. There is a pad separator spring that helps keep the pads from touching the rotor. You might check for binding of the pads in the caliper.

Ed Burdell

I think you're right. Without adhesive applied to the 996 antisqueal plate and the pad, the pad is free to do as it likes against the rotor.

The squealing is ghastly.