General Jack

Helllo all, new Porsche owner here, still getting to know my car, a 2011 Turbo coupe.

I get a little bit of noise/grind(?) when applying moderate to heavy pedal pressure at speed. Not sure if this normal. Its not brake squeal, rather something similar to ABS but it doesn't seem like ABS should be kicking in with moderate pedal pressure at, say 80 mph. Maybe it does?

I've checked my pads, fronts are down to maybe 5/16". I'm not getting a brake warning light.

Tracked at COTA last weekend and I have another event coming up. not sure if I'm imagining an issue or if what I'm experiencing is normal. Any feedback would be appreciated.

TT Surgeon

Ceramics?
Sounds like the abs grabbing a bit.
Cota, I'm jealous.

General Jack

Ah, sorry, should have mentioned they are steel brakes.

I'm going to take another drive this afternoon and ramp up the pedal pressure to see when the sound/feeling kicks in.

Yes, COTA is awesome!

General Jack

So drove the car again, and again with moderate pedal pressure there is a low frequency noise, something akin to a grind although not explicitly audible. Seems to be coming from the rear brakes. I pulled the wheels off and there is a fair amount of pad left. The sensors are still attached and I'm not getting any warning lights.

Is this normal?

boxster-r

I had also a problem on my rear steel breaks also, but it was more a squeal. I changed my rear pads by myself. After installing the new textar everthing is fine for now.

I found one problem. One pad was not correct glued on the damper, the clue pad was not in the middel and the pad was a little bit stucked. I belive the pad was not free in break and this causes the noise after heating up.

In your case, maybe your rear disk has a problem. The rotor where maybe overheated and are now not in perfect center anymore.

General Jack

Mine definitely isn't a squeal...

Disk looked clean, surface was smooth.

boxster-r

As i wrote, i belive the disk/rotor is gone. Maybe you should check this in a Porsche shop.

General Jack

Wow, that would suck. Thanks

TT Surgeon

No not normal, you may have cooked the fluid at the track, warping the rotor. Hi temp brake fluid is mandatory for any track work in a turbo. The oem fluid will boil.

jcnesq

If you need new rotors, be thankful you have steel brakes, not that terribly expensive.

My PCCB's had bad squeals early in life, and recently developing again. My wrench told me to do some high speed braking to get rid of glazing, and eventually (I think) he pulled the pads and ground the glaze off. I don't use 'em like I should and need to head out for an "Italian tuneup" soon.

General Jack

Yes, I had the system flushed and used Castrol SRF for the event so I shouldn't have boiled the fluid. Could rotors warp without boiling the fluid?

General Jack

No kidding, its the reason I didn't go with an S.

I learned my lesson last year burning through my pads and scoring the steel brakes in my F430. Thank God I didn't have the ceramics in that car either.

General Jack

I think that I have OEM pads. Would they put down a layer of material on the rotors after a couple of tracks days that I need to scrub through?

TT Surgeon

Can you record it in a iPhone video? Might help.

General Jack

Couldn't get a video to reproduce the only faintly audible low frequency "grind."

However, believe that I have diagnosed the problem as the rear brake pads getting thin which is developing a minor, but just barely audible vibration which has some similarities to the feeling of ABS kicking in (except in my case its only coming from the rears).