08-10 SS Turbocharged General Discussion Discuss the 2008 - 2009 Chevy Cobalt SS Turbocharged. On sale since the second quarter of 2008.
View Poll Results: When did you first notice rotor scoring/grinding? If no issue, how many mi on SS/TC?
Problem @ 1-5000 mi
136
25.61%
Problem @ 5001-10000 mi
83
15.63%
Problem @ 10001-15000 mi
40
7.53%
Problem @ 15001+ mi
39
7.34%
No Problem @ 1-5000 mi
43
8.10%
No Problem @ 5001-10000 mi
24
4.52%
No Problem @ 10001-15000 mi
18
3.39%
No Problem @ 15001+ mi
30
5.65%
Voted just to see results
118
22.22%
Voters: 531. You may not vote on this poll

Wearing rear brakes? Come in

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Old Jul 30, 2009 | 06:57 PM
  #351  
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Originally Posted by ElDude
Um..... I am getting a pair of rear rotors and pads in a few days.. They are free, because I kept my warranty.

I told the GM head tech that the problem started at around 7k miles ( i have 15k now and rear pads are gone, rotors groved to hell) somehow, that is my fault

When I explain "Well sir, the problem actually started at 7 k miles, I am just a newb and didn't notice) He says OK.

**** the system, whatever it may be. Government, cars dealership.
I had my rotors resurfaced yesterday, at my expense, with 4400 miles. "Wear attributed to debris."

Next time you won't be covered.

Billdayton
95 Corvette, 09 Cobalt SS, stock
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Old Jul 30, 2009 | 09:19 PM
  #352  
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The car is at the dealer right now... resurfaced the rear rotors (looked horrible) and they'll be putting on new pads tomorrow all under warranty, no hassle.
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Old Jul 31, 2009 | 10:19 AM
  #353  
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Complaint submitted

#10278862
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Old Jul 31, 2009 | 10:20 AM
  #354  
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The point of the ODI complaints is so that it gets documented. I'm not sure we have enough SS/TC owners to generate interest by the NHTSA to formally request GM to issue a recall, but the collection of complaints ought to help your case when you argue with the dealership.
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Old Jul 31, 2009 | 12:57 PM
  #355  
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Good luck! Brakes, both pads and rotors, and clutch facings are normal wear items with very few exceptions. This is a link to a GM page talking about brakes. You may find it informative even if you don't agree with it.

http://www.procutinternational.com/supplier_gm.aspx
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Old Jul 31, 2009 | 01:24 PM
  #356  
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From: Kathmandu
Complaint submitted. 10278867
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Old Jul 31, 2009 | 03:02 PM
  #357  
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NHTSA complaints

Originally Posted by SSlobalt
Complaint submitted. 10278867
That makes 13 complaints - 6 on 08s & 7 on 09s. Still not enough to get NHSTA's attention, but better.

I read something on their website about a petition for defect investigation, and will look into it further. In my last job I was the regulatory affairs manager, so I understand a little about how government agencies work.

Billdayton
95 Corvette, 09 Cobalt SS, stock
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Old Aug 1, 2009 | 09:35 AM
  #358  
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NHSTA Complaints

18 complaints - 10 on 08s & 8 on 09s

Billdayton
95 Corvette, 09 Cobalts SS, LSD & Performance gauges only.
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Old Aug 1, 2009 | 01:38 PM
  #359  
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From: chi-town!
just entered my complaint...#10279034

if every person (that complained on the forum) took the time to register and "complain" we would have alot. it takes less than 5 minutes. if i can do it (zero patience) anybody can do it!
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Old Aug 1, 2009 | 03:47 PM
  #360  
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I got a call back from the CAC. Since I had my rear rotors turned at my expense ($96...), with 4400 miles, they will be sending me a certificate for $100 in maintenance, good at any GM dealer. It can do some good to call CAC, after all! Maybe we are getting their attention.

The pads are not contacting the rotor evenly, and unless they polish out, I expect more scoring. I know the next time this issue pops up, I will bring a print out of all the NHSTA complaints.

billdayton
95 Corvette, 09 Cobalt SS
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Old Aug 1, 2009 | 05:56 PM
  #361  
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ogc
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Spoke with the owner of a race shop today he took a look at my rotors.

Plain and simple the problem is low quality rotors.

You have a hard compound aggressive pad, working on shitty ass metal.

No matter how many times you replace or machine these rotors with stock pieces you will continue to have this problem. We need a proper aftermarket alternative that was constructed to handle the types of pad that will be used on it.

If you switch to an aftermarket NAPA brand pad the problem will go away.

So the issue is that they did not properly match the pad to the rotors being used.

Less aggressive pads and the problem will disapear, better rotors problem will disappear. OEM rotors and OEM pads, no matter what, problem will reoccur.
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Old Aug 1, 2009 | 06:08 PM
  #362  
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How did they come to the conclusion it is the rotors?

It's the OEM pads. I have seen this happen on other makes/models with OEM pads. The OEM friction material chews grooves into the rotors within 1000 miles. The stock pads on my 00 Crown Vic destroyed all 4 rotors. I swapped the pads and all was fine, but the rotors were shot.
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Old Aug 1, 2009 | 06:44 PM
  #363  
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Originally Posted by metroplex
How did they come to the conclusion it is the rotors?

It's the OEM pads. I have seen this happen on other makes/models with OEM pads. The OEM friction material chews grooves into the rotors within 1000 miles. The stock pads on my 00 Crown Vic destroyed all 4 rotors. I swapped the pads and all was fine, but the rotors were shot.
The pads are ferrodo's they are a good pad.

The problem arises from the interaction of an agressive pad and a rotor that cant handle it.

The pads bite hard and heat the rotor up softening it further, then its a combination of pad material build up. As soon as that extra material is built up and you apply the brakes, it just digs right into the rotor causing the grooves.

It also has something to do with the gases not being vented properly.

If we had a rotor that was built out of a better metal, more abrasive resistant, and had either cross drilling or slotted to vent gasses this problem would not occur.

He also said the reason for uneven wear that people are seeing is likely do to the caliper design. Piston is on the inside so more pressure is put on the inside pad, also why thats why the grooving occurs worse there.

Im not 100% guaranteeing any of this, but it makes perfect sense to me, he said he sees the same problem on the SRT8 jeeps, chargers etc. Even on the older Vipers.
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Old Aug 1, 2009 | 07:17 PM
  #364  
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I see the same problem on stock brakes like on my 00 Vic. Once I went to aftermarket brake pads, I never had a problem with the stock rotors. It's the pad formulation.

My 09 SS/TC has Hawk HPS pads on the rear, just about 1000 miles on the stock rotors w/ the HPS pads. The rotors are smooth. I can't say the same for the FRONT rotors with the OEM Ferodo brembo pads. The Ferodos aren't as good as the HPS pads. They dust a lot and seem to be chewing up my front rotors. I can feel *slight* grooves on the surface as well - again these are the STOCK front brakes on my SS/TC. My stock rear rotors are fine with the HPS pads. I installed the HPS pads as soon as I brought the car home (less than 10 miles on odometer).

I still don't believe the stock rotors are at fault on the rear of the SS/TC's. It's the pads because everyone that has swapped to aftermarket hasn't run into the grooving issue again. Those that went and replaced the stock pads with stock pads still had the grooves!
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Old Aug 1, 2009 | 07:35 PM
  #365  
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Originally Posted by metroplex
I see the same problem on stock brakes like on my 00 Vic. Once I went to aftermarket brake pads, I never had a problem with the stock rotors. It's the pad formulation.

My 09 SS/TC has Hawk HPS pads on the rear, just about 1000 miles on the stock rotors w/ the HPS pads. The rotors are smooth. I can't say the same for the FRONT rotors with the OEM Ferodo brembo pads. The Ferodos aren't as good as the HPS pads. They dust a lot and seem to be chewing up my front rotors. I can feel *slight* grooves on the surface as well - again these are the STOCK front brakes on my SS/TC. My stock rear rotors are fine with the HPS pads. I installed the HPS pads as soon as I brought the car home (less than 10 miles on odometer).

I still don't believe the stock rotors are at fault on the rear of the SS/TC's. It's the pads because everyone that has swapped to aftermarket hasn't run into the grooving issue again. Those that went and replaced the stock pads with stock pads still had the grooves!
The stock Ferodos are more aggressive than HPS pads. so Yes they would not cause the same problem.

HPS for track use is not better.

Originally Posted by metroplex

I still don't believe the stock rotors are at fault on the rear of the SS/TC's. It's the pads because everyone that has swapped to aftermarket hasn't run into the grooving issue again. Those that went and replaced the stock pads with stock pads still had the grooves!
As I said, the stock rotors are the problem if you want to use more agressive pads.

If you use less aggressive pads like HPS or an aftermarket non performance pad you will not have any problems.

It is the combination of the pad compound + rotor

the rotor cannot hold up to the pads currently on the car.

get a better rotor problem solved.

change to a less aggressive pad, problem solved.

You can look at it from either perspective, yes the pads are to blame because they are to aggressive.... or the rotors are to blame because they cant withstand the pads.

Last edited by ogc; Aug 1, 2009 at 07:40 PM. Reason: Automerged Doublepost
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Old Aug 2, 2009 | 03:11 AM
  #366  
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Originally Posted by ogc
get a better rotor problem solved.
If only that were possible.
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Old Aug 2, 2009 | 04:42 PM
  #367  
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From: Quebec city, Canada
Originally Posted by Frank B
The car is at the dealer right now... resurfaced the rear rotors (looked horrible) and they'll be putting on new pads tomorrow all under warranty, no hassle.
Got the car back friday pm. They ordered new rotors because they had to shave way too much metal off of them and weren't comfortable with the whole thing. It was that bad.

The oem pads suck. And we're talking rear brakes here, they should last at least twice as long as the front brake pads.

It doesn't make any sense to be putting such poor quality pads on these performance brakes.

GM
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Old Aug 3, 2009 | 04:21 PM
  #368  
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Just wanted to chime in... I've got 7,000 on my car... and so far it looks like the pictures posted dont have anything on the current gouging I've got going on... They just started making noise today.

I just filed my NHTSA complaint.

Last edited by fulloutpwr; Aug 3, 2009 at 04:38 PM.
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Old Aug 3, 2009 | 04:58 PM
  #369  
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Originally Posted by Frank B
Got the car back friday pm. They ordered new rotors because they had to shave way too much metal off of them and weren't comfortable with the whole thing. It was that bad.

The oem pads suck. And we're talking rear brakes here, they should last at least twice as long as the front brake pads.

It doesn't make any sense to be putting such poor quality pads on these performance brakes.

GM
You have that completely backwards. The rear brakes except the pad are anything but performance.
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Old Aug 3, 2009 | 07:39 PM
  #370  
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Sorry, I'm not buying it. My inner rear pads went metal to metal twice in 12000 miles. Yes the rotors needed turned both times, and the last time they replaced the calipers, but if the pads are so good why did just the inner rears wear away? And wear away fast. There's more to it than that.
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Old Aug 3, 2009 | 08:00 PM
  #371  
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Originally Posted by redninja6r
Sorry, I'm not buying it. My inner rear pads went metal to metal twice in 12000 miles. Yes the rotors needed turned both times, and the last time they replaced the calipers, but if the pads are so good why did just the inner rears wear away? And wear away fast. There's more to it than that.
Because thats where all the pressure is being applied.

the piston is on the inside rear of the pad.

There is more at play here, the rear braking system just was not well put together.

And again I could be wrong, but I'm just putting my observations and that of some professionals I have spoken to.
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Old Aug 3, 2009 | 08:51 PM
  #372  
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At 4400 miles, both of my rear rotors were scored badly, but the inside was scored much worse. I had the rotors turned and the pads were inspected, showing very little wear. Now that I have driven the car for a while, the rotors are showing wear on all contact surfaces. That's a good thing.

This single observation suggests to me that the pads are too aggressive, or the rotors too soft, whichever way you want to look at it. If I had continued driving, the rotors would probably torn up the pads, as well.

Billdayton
05 Corvette, 09 Cobalt

Last edited by Billdayton; Aug 7, 2009 at 07:06 PM. Reason: correction
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Old Aug 6, 2009 | 04:28 PM
  #373  
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Everyone whos posted a similar problem needs to take the 5 minutes and file an NHTSA complaint so this can be remedied.
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Old Aug 6, 2009 | 05:24 PM
  #374  
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I have been watching this tread for awhile, so me and the tech at work decided to take a look at rears at 12,500 miles. Now I had grinding noise start at around 3000 miles. When we looked at the outboard rear it was about 80%, looked at the inboard on both sides all the way down to 15-20%.
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Old Aug 6, 2009 | 06:41 PM
  #375  
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Originally Posted by ogc
You have that completely backwards. The rear brakes except the pad are anything but performance.
No, I don't actually. The rear brakes on 08+ are not "perfomance" brakes, everyone knows that unless they don't know what they're talking about. They're a tad bit bigger than average and that's it.

I'm refering to the whole concept of putting a performance oriented brakes setup on a car yet putting on poor quality parts (ie: pads) which is obviously the case here. It's nonsense.
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