MThomas

My 2014 Z51 Stingray was having some serious brake pulsating. I have never had the car on the track. I even downshift to avoid using the brakes as much as possible. The dealership replaced all four rotors under warranty. The brakes were normal at first, however after about 1000 miles the brakes started pulsating again.

I returned to the dealership and the service tech couldn't believe how bad the pulsating was. He contacted their tech support and was told just to remove the rotors and turn them.

Is anyone else having issues like these?? THANKS!!

BigJoe

6200 miles on mine and no pulsing under light or heavy braking. What mileage did it start the first time? Early/late VIN?

MThomas

About 6000 miles. Early production....last for of vin 2835

sandu002

Z51 with 6200 miles, vin # 3928 no pulsating. Two track days, 3900 mile trip and 3 autox.

Jim Barker

I have had these issues on previous gens and on new Corolla plus, but at 7000 miles on this C7 standard brakes they are clean, best match I have ever seen pad to rotor and street driving it still feels like my 12GS brakes. I guess I should knock on wood!

mjw930

Did they replace the pads when they did the rotors? 90% of rotors diagnosed as warped aren't, it's pad material buildup and once that happens cleaning the rotors and replacing the pads are the only solution. Replace one but not the other and the problem comes back.

MThomas

The dealership did not change the pads. They said no reason to go figure. Thanks for your reply

Cruiter

15,000 + on my Z51 and no pulsating or loss of brake performance nor any squealing . And I've used them pretty good.

ZL-1

Just curious, were the wheels ever removed during those first 6000 miles? I ask because over the years there have been many GM service bulletins emphasizing the importance of proper lug nut torque and avoiding over tightening. But still you see many dealer techs and tire store techs tightening down the lug nuts with just an impact gun, extra tight, without checking with a torque wrench. This can cause uneven stress on the hat area of the rotor leading to runout and pulsation. The pulsation doesn't occur immediately, high spots develop after the car has been driven a while, then the customer returns complaining of brake pulsation. Often the connection isn't made because the pulsation doesn't occur immediately.

Also curious if the lug nuts were properly torqued after the second set of rotors were installed?

MThomas

Yes the wheel were removed just after I brought the car home. I like to get some wax on the barrels of each wheel. I have a torque wrench and ALWAYS check.

I was in the service area and watched the tech use one as well.

I would just like to get to the bottom of the issue for sure.

Rkvoss

This might explain it - see the vendor link as well.
https://www.corvetteforum.com/forums...es-warped.html

sflac7

I have felt the slow speed, 20 - 0 mph judder after every repair attempt except for the last, but I don't have many miles on the car after the last repair attempt. I have also felt a very slight shake in the steering wheel while medium braking from 55-45 mph.

Car was purchased 1/14. Noticed first juddering during first 3k miles.
2014 C7 Z51, M7, Convertible

Repair attempts:

1) replaced front rotors / pads
2) turned front rotors
3) checked wheel lug torque
4) turned front / rear rotors

Put GM on notice for final repair attempt

5) replaced front rotors / pads

As I said before, judder has not come back, yet. However, I've only put a couple hundred miles on the car since last repair.

Car has never been tracked and has seen only standard street duty.

All repair work has been handled by a single dealer, and under warranty.

jimmyb

Have you burnished these pads? If not, then, based on your driving habits (not good or bad, they are what they are), I would say this will happen yet again. There are numerous threads on this forum about the importance of burnishing Z51/Z06 brake pads. These are PERFORMANCE pads, if you are not tracking the car, you would be well advised to buy more street friendly pads and also have the added bonus of less dust.

The sad part of this is that what you are experiencing is NOT warped rotors (even though that's what get's blamed 9.9 out of 10 times)....it is uneven pad material adhering to the rotor surface because the pads weren't properly burnished. This is covered on page 9-8 of the 2014 owners manual. Frankly, I am surprised that GM continues to warranty these claims (which are clearly not their fault). Z51 is a "track" package, it's clear that folks don't appreciate the difference between track capable brake pads (and how to take care of them) and regular street pads.

Jimmy

sflac7

The manual states that burnishing is for competitive / track use. I understand that it could be helpful for regular street driving, however, it is not stated that it should be done for normal driving, nor should a manufacturer design a brake system that requires this procedure for normal driving conditions considering the vast majority of cars will not be tracked.

jimmyb

Agreed, the manual does not go far enough in it's explanation. Any track capable pad must be burnished, regardless of it's use. There is tons of information out there about this from StopTech and other brake companies. Again, my suggestion would be to have street pads (Carbotech 1521 for example) installed and I would wager this issue will NEVER come back.

GM is in a no-win situation with this. Reality is that NO one will ever come close to Z51's capability on the street (or the base car for that matter). But, the Z51 is the "track" package so it has to have "track" pads.

Jimmy

JerryU

Agree I've been a bit surprised at the number of folks who complain about squealing and the dealer removed the pads and puts on some brake lub! I know they get $$'s to do this from GM but I had to bed my pads twice to eliminate the loud squeal when I had about 1000 miles on the car. It went away and never came back. I even put on Carbotech 1521's, which are street pads to get ride of the excess dust and followed the Carbotech bedding procedure. It's a slightly different procedure. Most pad replacement calls for bedding the pads!
Frankly lots of folks got the Z51 because of the low price of they liked the wheels and spoiler but don't want to follow or don't what to read the manual and find out how to check the oil level! Then it gets overfilled, oil out the air cleaner etc! Apparently some dealer mechanics helpers do't follow it either when changing oil and go by the volume data in the manual!

sflac7

I get it about folks buying the Z51 package for certain items. I certainly did. I'm an engineering freak and wanted the E-LSD, dry sump system, trans and diff coolers and especially the mag ride option, which required Z51. Wasn't expecting track pads and associated issues.

JerryU

I bought for the same engineering reasons as I did my '08 Z51 and my '93 and '88 std shifts with HD suspension. I was not happy with the brake dust in the C7 but understand why they use those pads for tracking or very hard use. I switched to Carbotech 1521 pads, easy to do and 80% less dust. IMO they stop even better when cold and about the same with normal driving. But they are not for tracking.

SteveSoCal

ahhhh yes, then good 'ole money shift

rmarks

see:

http://www.stoptech.com/technical-su...nd-other-myths

Carrol Smith - Brake Bedding - he is the guru