Chipforbogey

I’m in my 3rd 992. This one has brakes squealing a whole lot more than the first two. This one continues even after being driven for a while and it seems to be getting worse.

Any thoughts?

Many thanks.

Jimmy-D

Have you washed your car/wheels recently. I find this helps

22992

Did you bed them in? Mine squealed until I pressure washed them really well and then bedded them in properly.

detansinn

PCCBs or iron rotors?

crazygordon297

I have the same problem, how do you bed them? Dealer looked at and gave me a Porsche bulletin that brake squeal is normal. I don't see how this is normal.

Richard_Wallace

I have found that with porsche both the PCCB and Iron you really have to bed them in.

If you haven't - take your car up to around 35 mph on a clear back road, do a couple of moderate breaking sequences 3-4 times from 35 to 5mph. This will start to heat them up.

Then take your car to 55/60 mph down to 5mph do this with hard breaking, not enough to trigger the ABS, but harder than you think you need to - just before the point of what I would consider emergency breaking. Do this 3-4 times. You will be surprised the difference it makes in both noisy breaks, and also I think it reduces break dust (specifically in iron breaks).

PCA1983

Some sort of coating glazes up the rotors with gentle use. When they start squealing, find a highway with thin traffic and hit the brakes hard from 80-90 mph down to 20-30 or so.
You might have to do this twice, but that squealing goes away for a couple of weeks.
Then repeat.
That's just the way it is, if u are too gentle with the brakes in your daily driving.

Brosef

agreed with this, although I think you are supposed to repeat this at least twice what you suggested.

there was a good white paper report on this topic that I read a few years ago. I want to say it was StopTech that published it. but the most basic premise is that when you brake the pads in properly, a thin coating of the pad material adheres to the rotors. other possible culprits could be that the pads are ever so slightly too loose - uninstalling them and reinstalling them with new retaining clips would solve that if it were the true cause, but I would say it's less likely.

and an interesting point they made was that in some race car applications, by the time the rotors need replacement due to the time interval maintenance, the rotors are actually slightly thicker and heavier than they were new.

russbert

I don't remember where I found these instructions (Internet somewhere) but I found them useful and I have had ZERO brake squeal:

Anytime you install new brake rotors, brake pads, or both, it's advantageous to bed in your new brakes. Bedding in your brakes is just an industry term to explain breaking in your new brakes. Bedding in your brakes helps transfer an even layer of brake pad material onto the brake rotor which assists in smoother brake operation and improved braking power. Having a uniform layer of pad material on the brake rotor is essential to minimizing brake squeal and vibration. For this procedure, you will need a good stretch of road and no traffic.

Perform 3-4 medium stops from 45mph. Slightly more aggressive than normal braking. You don't need to come to a complete stop for each pass. This brings the brake rotors up to temperature so they are not exposed to sudden thermal shock.

Make 8-10 aggressive stops from 60mph down to 15mph. For this set of semi-stops, you want to be firm and aggressive, but not to the point where ABS activates and the wheels lock up. It's important to note that you don't come to a complete stop but rather a semi-stop (~15mph). Accelerate back up to 60mph as soon as you slowed down to your semi-stop.

The brake pads and brake rotors are extremely hot at this point and sitting on one point will imprint the pad material onto the surface unevenly. This can cause vibration and uneven braking.

You may notice that your brakes will start fading, and sometimes smoke, after the 6th or 7th pass. This fade will stabilize and will gradually recess once your brakes have cooled down to normal operating temperatures. Drive carefully as your brakes may feel softer for the next few minutes.

Try not to come to a complete stop and find a stretch of road where you can coast for 5-10 minutes, preferably without using your brakes.

After the break-in procedure, there may be a light blue tint on your brake rotors as well as a gray film deposit. The blue tint shows that your rotor has reached the appropriate temperature during the bedding process, and the gray film is some of the pad transfer material.

Some cars and trucks require two cycles of the bedding in procedure. This may be the case if you are using old brake rotors with new brake pads, or new brake rotors with old pads. This may also be the case if you don't think you fully heated up the brakes in the initial bedding procedure. In any case, it's required that you wait at least 10-15 minutes between each cycle as you don't want them to overlap.

ipse dixit

1. Make a series of 15 stops from 50 to 5-10 MPH. At the end of each stop, immediately accelerate to 50 again for the next stop. Run all stops continuously in one cycle.

2. During the 50 (60) to 5-10 MPH series of stops, the exact speed is not critical. Accelerate to approximately 50 (60) and begin the braking cycle.

3. A moderate braking effort is needed to properly bed in the rotors and pads. A stopping force of approximately 0.8G’s, or just short of ABS intervention is the level of pedal effort you are trying to attain.

NOTE: BEFORE COMPLETING THE BREAK-IN, DO NOT COME TO A COMPLETE STOP WHILE THE PADS AND ROTORS ARE VERY HOT! THIS WILL TRANSFER PAD MATERIAL NON-UNIFORMLY ONTO THE ROTOR, CAUSING A VIBRATION DURING FUTURE USE.

IMN

I understand this issue has been discussed at length, however i am hoping someone has additional advice. Have a 992 new rear brakes and rotors (992.615.415.A8). as the brakes get warmer the squeaking starts. first few stops very quiet, madness starts usually around 35km/h down to 0, high pitch, and its driving me nuts. I have performed the various bed in process from above, even had my shop remove, and used high temp silicone and re-install and still no luck.
My understanding is that the squeaking is "normal" but in and around 8km/h down to 0. Any ideas or advice would be greatly appreciated.
As a background, prior to purchasing the car it was very quiet during my test drive. upon purchase and due to safety the back brakes (Pads only) were replaced, first day of picking up the car noticeable loud squeaking, than realized that the rotors were not replaced, the dealer than replaced the rotors, sanded the brakes so in theory they are now like new with new rotors, no change in the squeak. the bed in process and silicone were done after the new rotors were installed.