asofine

Dealer said it was "normal." They also did a rotor density test and a general inspection of the brakes. Said all was "fine." Who knows?

Scrappy1972

Mine does the same - basically a grinding sound. It started after a low speed panic stop a year ago but I cannot see how that would create the issue. My 991 RS also has PCCB's and they're silent by comparison.

mqandil

Guys check for debris trapped between the handbrake drum & mating pad at your rear wheels. For some reason if you Own PCCB brakes.... that area is like a magnet and attracts and traps small rocks. Possiby small rocks trapped between wheel and caliper od gets flung into that area. I had to clean mine 4 times in the past 10 months and I only drive on main clear roads and never off roads. Some of the symptoms if you have the same issue, is you having trouble with your handbrake engaging or getting occasional error codes about the hand brake failure and that is usually a possible indication that debris is may be present and trapped. The bad news about this issue, Porsche refuses to sell the center piece of the disk brake assembly which houses the drum brake, and only sells the entire disk assembly as one unit at a price of $6000 per wheel. So to replace both disks is $12000 plus labor. Although porsche will sell you the handbrake pads that mates against this drum, but the bigger issue is the scored drum.

Ever since I discovered the issue I have been inspecting the handbrake drums regularly and removing all the debris and the annoying low speed grinding noises have disappeared. I have some damage to the drums, but I refuse to pay $12000 to install new ones as the main brakes are like new and the handbrake still operates great despite the scoring. At some point I will be removing the existing drums and take them to my lathe and machine off the scored drum outer surface to remove the scoring. There is plenty of materials left but of course you will need to adjust the handbrake as the gap got larger, which porsche dealer will perform free of charge. Hope this helps. Mark

mqandil

Mine said the same after taking it to them 4 different times complaining about the same issue and the answer has always been it is normal and there is no issue until my service mechanic decided to check the handbrake drums. See my comments regarding this in earlier post above. Please also see an additional attached picture. Mark

Crazy Eddie

It seems that this is a common issue?
I am thinking it may be more complicated than just a piece of plastic rubbing ( My thoughts? ) This was a thread discussing this and other things posted here https://rennlist.com/forums/gt4/9137...l#post13055960
I even posted a video here on dropbox ...
https://www.dropbox.com/s/jbpqwdcgn7...nding.mp4?dl=0
What I do find strange, is that I took the car to the track recently, and it seems to have stopped? ( Wondering if it was plastic that was just ground off ?? )
These are not PCCB on this car, my other car has them, and they don't rub or grind at all. It seems to be a rubbing issue, at low speed and breaking? In the video (which is a GoPro mounted to the cars tow hook) you can here the grinding as it comes through the chassis
Hope that helps
Regards
Ed

rdragon

Mark - What angle is this picture from? Are you able to see that area with car on the ground? What have you been removing the debris with (like a toothpick)?

Also, regarding the first sentence in your second paragraph...were you getting the grinding at low speeds or when braking at low speeds? Thinking the latter but wanted to make sure.

I followed the bedding procedures listed in these forums on two separate weekends but still get squealing here and there.

xxrockmanxneoxx

Mine started happening after i went to the track it was a light run but i went over some curbs. I started driving would hear it in the rear then it would stop. Im guessing its the rear brake duct like most have stated. I'll checking mine tonight to see if thats the case and loctite the screws and tape/ziptie the duct together.

mcdavis

I've had two rubbing issues:

1. My e-brake was out of alignment. Took ~2 hours of service work to calibrate. No rocks detected near my steel brakes.
2. I swear my brakes rub if I wash and do not dry the rotors, from rust...I realize it seems that the clearances would be much bigger, but it happens pretty regularly. Goes away after the first 1000' of driving.

-mark

andrewwo

So did they end up fixing it ? mine have same problem and been went back for 3 times.. they take off brake. then parking ,.. then check the shaft .. end up say everything is normal but noise continues...

I also have those mark on the parking drum ( on both side ) .. but only 1 side get noise...

andrewwo

Thanks for the video... it help to explain to the porsche workshop.. but still.. same " everything is normal" answer despite my 3 trip to them ,

how did you fix it ? by running hard for some time ?

andrewwo

is it end up to be the stone caught in the brake shoe or the scratch mark from the disc ( drum bell ) ?

VLJ

My experience with PCCB on two different cars is they are noisy brakes.
When clean at low speed you can hear the pad rubbing the rotor. When dirty at any speed they squeal like a horny pig.

Hwy

Thanks for this info. Exactly what I was after to solve my problem. 5 years later and it is still super relevant so I just want to keep this thread alive and going.