awsum1ed

I was driving one saturday on the freeway & side street and the temparture was in the mid to hi 80's. Normal driving conditions. And all of a sudden when
i hit the brakes i heard a loud humming sound! not a squeel! Has anyone out
there experince something like this on PCCB's? I have a 05 Turbo S only with 1500 miles on it. I have pampered this car since i drove it off the dealership.

It's disappointing to hear a superior brakes to fail if so? on
a 150K price tag automobile.


Any comment or adivce will sure be appreciated. I plan to take it to
the dealership.
_________________________
2005 Turbo S

Oak

The PCCB's often make strange sounds. Not indicative of a problem. A few have mentioned a grinding type of sound. It maybe harmonic issue due to pads and disk seating during break-in.

FWIU, the 05 turbos have the 2nd generation PCCB which seem to not have all the controversy and problems of the 1st gen.

BobbyC

I also have an '05 Turbo S and now with 11,500 miles on it and have not experienced "a loud humming sound" as you described it. Have it checked out. Although the brakes will squeal after heating up with only partial braking at low speeds...consider it normal for these ceramic composite pads.

However, if you have not already then do a proper "bedding-in" of the pads and rotors. This is important. Do a search on this forum and you'll find a detailed procedure on bedding-in. Good luck!

Garey Cooper

Why are you sure it is the brakes?

awsum1ed

To Gary Cooper, it seems to be the brakes, it only made that loud noise when i hit
the brakes. It seems to sound like metal to metal contact when your pads are worn!

BobbyC

Go bed-in the pads, and if the problem still persists then have it checked. To bed-in:...do 8-10 moderate to hard braking from 60>20 mph in quick succession...drive around for 10 mins without braking to cool...then do 4-5 hard braking from 80>30 mph and 1 final hard brake from 100 mph plus (if possible)...cool off. Pads are now bedded. If you smell "burning" from brakes, that's just normal Green fade. Good luck...

FixedWing

This might be a big part of it. The PCCB's especially, need to be used hard. They don't apprciate pampering.

Stephen

T2

I just changed the pads in my 03 X50 with Gen 1 PCCB's - I got 66k miles and 6 DE events on the original set - they like a progressive warming on the track (3 laps or so) and then hammer them - I just took it easy for one day on the new pads and then performed a series of progressive brakes as descirbed above and they new pads feel great. I have had instances where a pebble will get caught in them somewhere and squeal like hell for a second then fall out - maybe your ABS or PSM kicked in prematurely for some reason - just two thoughts. Good luck with them.

03-turbo911

No humming noise coming from my brakes as well. So far so good with these Gen II PCCB.