Rennen

I don't have but a hundred miles or so on them and the machine marks have just barely worn off the rotors. Should I try to fix this now or should I give them more break-in time and see how they're doing in a week. I put anti-squeal back pads on them but didn't do anything else. If I should fix them now, what can I do to eliminate this beyond what I've done? I've chamfered pads in the past but I'm not too hip on that since you lose surface area on the rotor doing that.

Bill Gregory

Normally, I put just a very narrow 45 degree file cut on the edges of the pads - not enough to really affect the pad surface.

What pads are you running? Are they new rotors? What's the condition of the calipers, ie, original or something else?

Rennen

I just put new Ferodos on there with new Zimmerman cross-drilled rotors. The calipers seem fine, but they are the OEM Bremobs.

JasonAndreas

StopTech has a new article online, Pad and Rotor Bed-In Theory, Definitions and Procedures that maybe worth trying.

KB964Cabrio

Glad i'm not the only one having a problem with new brakes squealing. I have just the the entire system renewed (original calipers), but new pads, new discs, new pipes etc. The rears are squealing like a pig, very annoying and very embarassing. I've spoken to the shop and they have said that this is a common fault on the rear brakes of early 964's and ther's not really anything that can be done, except an expensive upgrade to a newer rear disc system? any advice?

Christer

did you bed the pads in properly?

KB964Cabrio

Just read the article posted by JasonAndreas, the usual advice given to bed brakes in for street use is to use them gently for the first few hundred miles. However, after reading the link above, it's quite clear that there is a much better process... I think i'll be spraying some brake cleaner on the discs and starting with the bedding in process again...

Rennen

Thanks, this should be very helpful.

JasonAndreas

Find a new shop. How many other cars driving around do you hear with squealing brakes? I'll bet money your brakes didn't squeak when they came out of the factory! Did the shop clean out around & behind the spring plates when they had the calipers pulled off the discs? Did they replace the damping plates between the pistons and the pads? If your brakes still squeak after bedding them in (if you check the website for the manufacturer of your brake pads they will have proper bed-in procedures listed or follow the advice given in the StopTech article) you can buy rubber backing plates (sometimes they come with the pads) that go between the pad and the piston and dampen most vibrations and eliminate the squeaking.

Rennen

In my case, the shop was ME. Of course, I have not gone through the bed-in procedure specified by StopTech. I will do that later this week. I did thoroughly clean my calipers and I did install new damping material between the pistons & the pads.

KirkF

I had the same problem. No amount of cleaning or rebedding would do anything to help the squeal.
When the cars brakes got hot my porsche sounded like a bus stopping.

I replaced the stock pads with ceramic pads which squeal above the range of human hearing and leave far less brake dust on the rims. Worked like a charm. They arent too expensive. (And the ones I threw in the garbage were almost new like yours so don't feel bad about it.)

Kirk

Kahdmus

I had terrible, terrible sqealing. I changed to Ferodo pads which fixed the problem at first but then they started squealing again after a week or so (although not as bad). I removed the anti squeal stuff (it had gone all squishy and 'pulpy' and gave the caliper a vigorous cleaning, then reseated the pads. Only very minor and infrequent squeal since. In fact its only audible at all from inside the car when the window is down.

Rennen

I'm going to pull the pads this weekend, remove the ati-squeal backing and try to rebed them. If that doesn't work, I'm going to switch to Porterfield pads because I've had good luck with those in the past.

Bill Gregory

Just out of curiousity, has anyone tried the stock Porsche buttons for the back of the pads, to stop any squeeling?

darth

I had a squeal with OEM pads while applying the brakes at slow speeds. Cleaned up the Porsche buttons and replaced the half worn out OEM pads with Metal Masters. After bedding them in as described in Adrians book (i.e a few aggressive stops from about 80km/h) - no more squeals and a lot less brake dust. I'm not sure if one can bed in pads after they've been braking for 100 miles and I think new rotors may need to have the surface ruffed up to remove the concentric circles put in during the machining process which could be contributing to the squeal.

Hope this helps
Bill
90C2