hubris140

Hi folks

Seeing a weird issue with my car (currently have ~15k miles) and wanted to reach out to see if anyone else has some experience. I've been hearing a faint grinding noise on top of the usual squeaky noise from my carbon ceramic brakes (the noise can be best described as a sandpaper rubbing sound and feel on moderate pressure stops).

I took it into the dealer and they came back with 'brake pads prematurely wearing'. They are doing a one time courtesy replacement of the pads and are not giving me any more details other than that the new pads have a 'different design' and that the CC rotors are fine. They are not even returning the old pads so I can assess the damage or wear.

My concern is that by not learning anything about what caused this issue in the first place, what would happen if the new pads would also display a similar issue after some miles and the shop refuses a replacement? Has someone else gone thru this process?

Background on my car - 90% of the miles are freeway miles. One autox session and a few canyon carving sessions in the past yr. No HDPE/ track miles and maybe about 4-5 hard stops (100 to 50 mph) on the freeway. I burnished the brakes around the 2k mile mark and the brakes have been squeaky ever since. No observable degradation in stopping performance.

Any advice would be appreciated.

Bill Dearborn

For what its worth you could ask to see the old pads after they take them off the car. The Corvette mechanic at the dealership I go to always has the small parts laying around at the end of the day if I want to look at them. I doubt you would learn much about them and I doubt there is much the mechanic could tell you about why they wore and why the new part number might not wear as much other than maybe GM might have consolidated spare parts supplies on the ZR1 versions of the pads and rotors. No reason to stock two versions of the same thing if you can get the latest one at the same price.

Bill

hubris140

Thanks for the insight, Bill. I didn’t realize they may have switched over to the ZR1 pads. I will check with the mechanic.

SilverGhost

Thank you for confirming my suspicions! I burnished z51 ceramic pads according to mfr instructions and after that they squealed like a stuck pig. I left my new Z07 brakes "green" will never be tracked (vert). They are as silent as a Cadillac's binders.

hubris140

Yeah, my brakes were silent before burnishing. But folks on here say stomping on unburnished brakes at excess speeds >130mph might result in a dangerous “green fade” scenario where the bite disappears. Haven’t experienced this myself but makes you think.

CaddyRacer

NB AC Delco/brembo brake pads come with a 24m warranty

hubris140

Does this apply to replacement pads or only pads that come factory installed on the car? I’m asking because I’m wondering if this issue repeats with the new pads can I have them be replaced by the dealer as well?

RegnaR

what year is the car?

hubris140

2017 MY. Late 2016 build date.

hubris140

Hi folks, an update here - I got my car back from the dealership yesterday. They replaced all brake pads at no cost. They declined to show me the old pads and I was more concerned with how the car drove with the new pads. Happy to report that the squeaking and grinding noises have been eliminated (for now at least). Looking at the writeup of the issue below, seemed like the pads had cracks in them and some had uneven wear. Any insights here? As I mentioned earlier, I burnished the brakes around 2k miles and have not tracked the car yet.





The service advisor asked me to hold off on burnishing the new brakes though, which seemed weird to me. The brakes bite okay for now. While I understand the squeaking may come back if I burnish, I also don't want to put myself at risk of not being covered for new pads in the future, if the burnishing leads to cracks developing in the new pads. Thoughts?

BrunoTheMellow

7 mm to 10 mm is a huuuuuge uneven wear if true.

hubris140

I'm finding it hard to understand what may have caused this. Outside of one autox session and a few canyon carving weekends, I haven't put much stress on the brakes in the year I've had it.

BrunoTheMellow

I think they have no idea what they are talking about and didn't realize these pads come from factory with a beveled edge.

hubris140

I've never heard this before. Can you expand on this? Does this mean that all cars come with uneven pad thicknesses? If so, wouldn't they have seen the same when they unpacked the new pads for installation on my car?

(Not questioning your logic, I'm just trying to understand better)

Bill Dearborn

Interesting they only measured the rotor thickness Vs weighing them as they are supposed to do. I know the rotors have both a minimum thickness and minimum weight but the weight is the more important measurement. Might be interesting to ask the service writer why they didn't weigh the rotors if they were worried about them.

Bill

CaddyRacer

I would contact AC delco, I'd YES....I already wore out a set of AC delco Z06 CCB pads...I not bought ZR1 CCB pads
from Amazon site:
"Warranty & Support
Warranty, Parts:24 Month / Unlimited Mile Limited Warranty on parts sold on or after 04/01/18. (Parts Only) Please see ACDelco.com for more details"