Are my brakes warped?
08-28-2014, 02:13 PM
#41
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Update on this as I am the OP. Drove it around another 1000 miles with the hope it would clear but no luck. Brought it to the dealer last week for the passenger seat recall (parts had to be ordered) and the brakes pulsating. They "re burnished" the rotors and it felt better. Last weekend took a road trip and the pulsating came back. Car went to dealer this morning for recall parts to be installed and now they are replacing the rotors and pads! Parts will be here tomorrow morning so they are leaving the car in the service department indoors overnight.
Great dealer. Heritage Chevrolet in Chester, VA, they sell a ton of High End Camaros and were one of the first in the state to have the ZR1 when it first came out. They've sold about 40 C7s so far.
Great dealer. Heritage Chevrolet in Chester, VA, they sell a ton of High End Camaros and were one of the first in the state to have the ZR1 when it first came out. They've sold about 40 C7s so far.
Last edited by VAmikeC7; 08-28-2014 at 02:17 PM.
08-28-2014, 05:42 PM
#42
Drifting
Mine started doing this at about 8K miles also. Very subtle but definitely there. I don't use the brakes heavily, never tracked or raced so no clue why it would suddenly act this way. hoping it gets no worse.
08-30-2014, 10:02 AM
#43
Supporting Vendor
It looks like there are a good many issues like this if we see them reported here this much.
Without ruffling feathers - the fact IS that your rotors are very unlikely to be warped. Furthermore - you can only diagnose that with a runout gauge so a test drive by a dealer tech does not confirm this.
What is almost certainly the case is an inconsistent transfer layer on the rotor surface. This can lead to several symptoms - all of which are unpleasant when driving.
Pulsing in the steering wheel, brake pedal, and the entire car shaking under hard braking which is amplified at higher speeds.
The root cause of this varies. Poor break in, sudden heating/overheating of the pads/rotors, abrupt braking etc. The transfer layer is constantly refreshed by the abrasive components of the brake pads. If it's uneven then friction changes as the wheel rotates. That is that feel of the car slowing unevenly as you roll to a stop. The pads grip unevenly as the rotors go around.
It's not always visible - but a severe case on a track car had the front wheels coming off the ground under hard braking into T1 at VIR.
The fix is cleaning the rotor surface by some method and rebedding the pads. Not always easy. However since you are under warranty it is just as easy to install new pads and rotors. That might be wasteful but the problem goes away.
However - drive in the same manner and it will re-occur. So lather/rinse/repeat.
I would suspect lighter use of Z51 cars are the worse culprit. The pad compound there is clearly more aggressive so a stab at the brakes when cold could easily strip a portion of the transfer layer off. OR sudden hard use when out driving.
The brakes are designed to take harder than normal street use.
I have a good scanned article to post and this needs an edit to get to the cliff notes which I will do later.
08-31-2014, 10:14 PM
#45
If the lug nuts are tightened during PDI with an airgun they can be very unevenly torqued. This used to produce warping in earlier series. With my C5 I always hand torqued to 100 ft lbs and had no warp problems although warping was a very common issue. First thing I did when I got the C 7 home was hand torque the lugs. No trouble yet but still early. Strong believer in hand torquing!
Many years back I had rotors warping constantly. When I started hand torqueing after any shop touched the lug nuts, the warping was drastically reduced.
09-01-2014, 09:55 AM
#46
Burning Brakes
A little bit of knowledge is sometimes dangerous. Doesn't make me want to buy their product. I have only seen a small change in the attitude of Dealer Tech's that are too lazy to torque wheels. Did run into some at Infinity dealer where I had tires drop-shipped to! That reminds me just had rear shocks changed better go loosen and torque rear wheels!
09-01-2014, 10:20 AM
#47
Le Mans Master
I have a feeling that the factory is over torquing the lug nuts because the calibration is out. It would be interesting to see if all these vehicles were made in the same week.
09-01-2014, 10:25 AM
#48
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Well, it could be a combination of materials (too soft and/or inconsistent) and/or design (made too thin for the sake of saving weight, or bolt holes not right) and/or build (over-torquing). If we see much more of this, there's definitely a third-party opportunity for improving brake reliability.
09-01-2014, 10:42 AM
#49
Burning Brakes
Unless you have been tracking the car, I would be very surprised if you have warped rotors with just a few thousand street miles on them. Based upon your description, I would suspect the rotors may be glazed. If that is the case, lightly sand them with a fine emory cloth, pads too, then rebed the pads. Sometimes you can "break" the glaze with a couple of hard stops from 60 - 70 mph...might be worth try before you pull things apart.
09-03-2014, 03:41 PM
#50
Instructor
Brakes vibrating
I would love to see article....I have 11k miles on Z51 stingray....getting my second set of rotors....brakes are pulsing/vibrating. I drive this car just like I drove my C5.......I open it up sometimes. Tech is telling me last set of rotors that I get under warranty....sounds like B.S. There is a problem with rotors/brakes...something is wrong. looking forward to article.
It looks like there are a good many issues like this if we see them reported here this much.
Without ruffling feathers - the fact IS that your rotors are very unlikely to be warped. Furthermore - you can only diagnose that with a runout gauge so a test drive by a dealer tech does not confirm this.
What is almost certainly the case is an inconsistent transfer layer on the rotor surface. This can lead to several symptoms - all of which are unpleasant when driving.
Pulsing in the steering wheel, brake pedal, and the entire car shaking under hard braking which is amplified at higher speeds.
The root cause of this varies. Poor break in, sudden heating/overheating of the pads/rotors, abrupt braking etc. The transfer layer is constantly refreshed by the abrasive components of the brake pads. If it's uneven then friction changes as the wheel rotates. That is that feel of the car slowing unevenly as you roll to a stop. The pads grip unevenly as the rotors go around.
It's not always visible - but a severe case on a track car had the front wheels coming off the ground under hard braking into T1 at VIR.
The fix is cleaning the rotor surface by some method and rebedding the pads. Not always easy. However since you are under warranty it is just as easy to install new pads and rotors. That might be wasteful but the problem goes away.
However - drive in the same manner and it will re-occur. So lather/rinse/repeat.
I would suspect lighter use of Z51 cars are the worse culprit. The pad compound there is clearly more aggressive so a stab at the brakes when cold could easily strip a portion of the transfer layer off. OR sudden hard use when out driving.
The brakes are designed to take harder than normal street use.
I have a good scanned article to post and this needs an edit to get to the cliff notes which I will do later.
Without ruffling feathers - the fact IS that your rotors are very unlikely to be warped. Furthermore - you can only diagnose that with a runout gauge so a test drive by a dealer tech does not confirm this.
What is almost certainly the case is an inconsistent transfer layer on the rotor surface. This can lead to several symptoms - all of which are unpleasant when driving.
Pulsing in the steering wheel, brake pedal, and the entire car shaking under hard braking which is amplified at higher speeds.
The root cause of this varies. Poor break in, sudden heating/overheating of the pads/rotors, abrupt braking etc. The transfer layer is constantly refreshed by the abrasive components of the brake pads. If it's uneven then friction changes as the wheel rotates. That is that feel of the car slowing unevenly as you roll to a stop. The pads grip unevenly as the rotors go around.
It's not always visible - but a severe case on a track car had the front wheels coming off the ground under hard braking into T1 at VIR.
The fix is cleaning the rotor surface by some method and rebedding the pads. Not always easy. However since you are under warranty it is just as easy to install new pads and rotors. That might be wasteful but the problem goes away.
However - drive in the same manner and it will re-occur. So lather/rinse/repeat.
I would suspect lighter use of Z51 cars are the worse culprit. The pad compound there is clearly more aggressive so a stab at the brakes when cold could easily strip a portion of the transfer layer off. OR sudden hard use when out driving.
The brakes are designed to take harder than normal street use.
I have a good scanned article to post and this needs an edit to get to the cliff notes which I will do later.
09-03-2014, 03:44 PM
#51
Instructor
Brakes/Rotoe Issue
Third corvette...C4/C5 now Z51 Stingray. Getting second set of rotors on all four wheels. Car has 11k miles on it. Something is not right. Tech is telling me this is the last set I will get under warranty. This is B.S....something is not right with these rotors or brake pads or combo of both. GM needs to look into this and stop the nonsense.
Hey VAmikeC7,
I’m sorry that you have this concern with your brakes. It looks like you are asking the forum for some feedback, but might head to the dealership once TRC7 speaks with his dealer. Feel free to shoot me a PM if you decide to head in.
Austin J. (Assisting)
Chevrolet Customer Care
Hi TRC7,
I see you are already planning on heading to the dealership for this braking issue. If you could let me know how the dealership visit goes, I’d appreciate it. If you have any questions before or after your visit, send a PM my way.
Austin J. (Assisting)
Chevrolet Customer Care
I’m sorry that you have this concern with your brakes. It looks like you are asking the forum for some feedback, but might head to the dealership once TRC7 speaks with his dealer. Feel free to shoot me a PM if you decide to head in.
Austin J. (Assisting)
Chevrolet Customer Care
Hi TRC7,
I see you are already planning on heading to the dealership for this braking issue. If you could let me know how the dealership visit goes, I’d appreciate it. If you have any questions before or after your visit, send a PM my way.
Austin J. (Assisting)
Chevrolet Customer Care
09-04-2014, 07:27 PM
#53
Melting Slicks
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Are you guys checking the lug nut torques?
If you are having pulsing try that first. Let us know what happens>
If you are having pulsing try that first. Let us know what happens>
10-24-2014, 01:51 PM
#54
05-21-2017, 11:09 PM
#56
Burning Brakes
I would like to add my experience. I had pulsing in the braking on my C5 at low speeds and thought it might be warped disks. There was never any vibration in the steering wheel or pulsing in the pedal. I had the front rotors turned and it seemed to help a bit but then the pulsing came back. Then I had the rear rotors turned and it helped for a while and then the pulsing returned. Finally, I replaced all four disks (not expensive on a C5) and all the pads. The pulsing went away and did not return. A friend with a BMW had the same experience and fixed it the same way.
07-09-2017, 08:17 PM
#57
There appears to be a redesign. Dealers replace rotors in pairs because of the redesign. I'm having the problem with a C7 delivered in April 14 at 20,000 miles. I'm curious if the problem persisted into the 16s and I'm betting not.
By contrast I own a C3 that I took delivery of in January 68 that is still on the original rotors.
By contrast I own a C3 that I took delivery of in January 68 that is still on the original rotors.
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07-11-2017, 03:59 PM
#60
Drifting
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I can't remember the number but there was a Service Bulletin out on this problem. It called for the dealer to replace the two piece rotors and install one piece. My dealer did it without any problems.
