Mine have been squeaking since day 1 as well. Was told I am too easy on the brakes, Porsche is a sports performance car. I've taken it in 4 times and I assume they seat them (take it out and slam on the brakes a few times), squeaks go away temporarily and the next day, squeaking returns...... Feeling like I bought a lemon.
Understand how you are feeling, but the problem is with the dealership, not with the car. If they've had four opportunities to correct the issue and have not, then you should probably consider taking the car to a different dealership. Hopefully you have a least a couple to pick from in your area.
New cars, which have been sitting parked for a month or two during the delivery process, often have some rust on the rotors and the brakes may squeak a little. Usually this goes away in the first 1000 miles or so as the brakes bed-in. Thus, sales associates and service advisors frequently recommend working the brakes hard to accelerate the bed-in process. And, sometimes that works. But it is not a universal cure....as you are discovering.
The majority of brake squealing is caused by harmonics occurring at the metal-to-metal contact points on the brake calipers....also known as forced excitation. Examples of these contact points include:
- Where the caliper pistons contact with the back of the brake pad
- Where retaining pins and spring clips contact each other, the pad, or caliper
- The slide on a floating caliper
- Where the caliper bolts onto the spindle
The fix requires disassembling the caliper (but leaving the pistons intact); cleaning the metal-to-metal contact points to remove any rust; apply a thin film of high temperature / high solids anti-seize compound at all metal-to-metal contact points; and reassembly. This is why, when you buy a new set of brake pads, a small tube of anti-seize lubricant is often included in the box.
Some folks try re-surfacing the rotor (now hard to do on floating rotor designs) or changing pads. This will sometimes work, but all it really does is potentially shift the vibration frequency out of the harmonic zone. The root of the problem typically remains proper lubrication of the points described above.
In my experience, the biggest challenge folks face in fixing squealing brakes is finding a mechanic that has been trained on these fine points, and a shop manager that is willing to let the mechanic take the time to do the work properly.
If you can't find a dealership capable of correcting the problem, start looking around for a good independent shop.
Best of luck getting this resolved to your satisfaction.
