Ok, so I want to try to provide some information to the right people concerning this potential issue. If your rear brakes are wearing to the point where you can hear grinding noise coming from the rear or have visible scoring on the rotor please vote when you first heard/noticed this. If you have not had this happen yet please vote your current mileage.

Also, if you have gone to the dealer and they have told you there is no issue or it is your fault and you have not had the brake serviced yet it would probably be of good value to us all if you take pictures of your brakes. (preferably w/ wheel removed, aim for good resolution/lighting and take the following pictures: inner and outer rotor surfaces of both sides [4 pics] and pictures that capture the amount of brake pad material left to compare inner to outer) If you want to do this feel free to post them into the thread, but it might also be helpful to PM me with a link to wherever you host them and the last 8 digits of your VIN.

(note: I wanted to keep this separate from the other threads because of the poll)

EDIT: Pictures posted below of my situation, it would really be good if someone else having this issue pulled their wheels and checked to see if this is the same issue they are having

 

I first started hearing it and noticing it at 4000 miles. I currently have 5000 miles and it is getting worse...

 

3k and mine are grinding. Thought it was the fronts at first because of the "faulty" rotors blah blah. But without a doubt I heard the rears grind yesterday. Maybe its both? So sad...
Once xmas vacation kicks in im gonna pop the wheels and take a look at the pads (with pics)

 

I have had no problems.. .. I have 3000+ on mine. I even took it to the dealer when the recall first came out (I believe it was for the front rotors though) and was told that dealers are aware of a potential problem for the 08's produced around April 08...they said that they would replace them no questions asked when I wanted it done (even if a 'problem' does not develop).

 

have absolutly no problems...and i check every time i change my oil and so far they look brand spankin new!!!
but im actually thinking of just putting on the Power Slot rotors just cause they look good...

38,000ish miles

 

I voted No problem at 8000 miles. Produced July 31'st, 2008

Edit: WRONG! After inspecting the rears today using an inspection mirror, I find both inside rear rotors grooved about 5/16" in from the outer edge. Looks like around a .020 deep groove about .050 wide, but I'll keep an eye on them. I do all highway miles. Looks like from casting flash on the caliper mounting bracket rubbing the rotor during hard cornering. I didn't have an 18mm wrench to get the bracket off to file the flash today and a socket didn't get on the bolts square to break them loose.

The inside pads do appear to be wearing more than the outside though. Another thread on that led me to take a closer look.

 

he is asking ss/tc owners

 

subtle grinding from rear at 4k mi. Im now almost at 6k and have significant scoring and grinding in the rear. I have parts on order from my dealer who is going to be replacing the pads under warranty and machining the rear rotors...theyre also gonna replace the front rotors under the recall. We'll see what happens. Their reasoning for it happening was a "high metallic content" in the rear pads.

 

I have 7500 miles on my SS and no problems so far.

 

Tell them that is **** and that you want some sort of substantiation for that claim...

 

i hate to say it but i noticed within the first 5000miles(7000km), the pads still look good but i have yet to look on the inside of each rear rotor for indications of excessive wearing. My fronts are even ever so slightly forming grooves on them too........i'm gettin close to droppin by the dealership to get the problem noted on my file....

 

Just turned over 20k miles and last checked the brakes a few thousand miles ago when doing a tire rotation. I didn't notice any odd wear at the time (with just the slight/normal high metallic-content performance pad wear caused to the rotor surface). I'll check them out again a little closer but I haven't been hearing any noise.

 

Ok, so I think I figured out the problem with my brakes. It wasn't quite what I was expecting. When I felt the what I thought were the pads in the rear they felt extremely low. However, that was just an assumption because I couldn't see them. Upon removing the wheels and checking the brakes I noticed a feature on the rear passenger caliper mounting brackets that is colliding with the rotor and is making a groove in the rotor. This would explain the grooves in the passenger rotor and the grinding noise I hear.

On the driver side the matching feature is not contacting the rotor. There is a small groove in the rotor but I don't see what exactly is causing it.

The pads on both sides actually are very equal in material left so I definitely was wrong about that. At least I did find a problem so I know that I'm not going crazy. Its very easy to see why the dealer missed it to. I don't think they removed the wheel and looked at it on a lift. To see the feature on the bracket the wheel needs to be removed and you need to be looking from the top.

Passenger rear outer rotor

Passenger rear inner rotor

Passenger rear inner rotor

Passenger rear inner rotor

Driver rear inner rotor

Driver rear inner rotor

Driver rear inner rotor

Driver rear through caliper (pad material check)

Driver rear outer rotor

 

^^^^^mine are looking pretty much the same.........warranty work??

 

Oh, if you can't tell what I'm talking about the part of the bracket making contact:



With this feature being on the bracket I'm thinking if the rotors aren't too deeply grooved (apparently my case according to dealer, .020" scoring, .059" is allowable) then all this will need is a grinding of the feature. The only amount the rotor and the bracket should move relative to each other is the deflection caused by the brake caliper activating. If they are free and clear by a few millimeter we shouldn't have any further issue.

Anyone else concur or disagree with that thought?

 

Why do you guys ride your brakes ? I have 4k on mine and the pads are almost 100% intact. That other post was talking how the clip is grinding the rotors .... Thoughs pics surely aren't the case. Looks like some really bad stop and go driving ... If you joy ride your car and are doing a lot of city driving I am sure the pads will wear just like any car in the service industry. Trying to keep pads on service vehicles is a headache from all the stop n go driving. I hear cops/delivery trucks. Alls sortsa vehicles who are hard on the brakes squealing and grinding because they drive like that.. Seeing how fast you can go from street light to street light will make any pads wear excessively ... The demographics for the Cobalt SS drivers clearly show how its mostly young drivers who buy these cars and honestly probably should have stuck with the LT models from lack of experience and common sense. Brakes wear just like bearings and every other moving part on a vehicle .. Brakes aren't meant to last 100k with out ever being replaced. I wonder if people think the oil never needs changed too...

 

Krispy, so ypuve got some casting flash that is too close to the rotor, and when it flexes it contacts this extraneous casting junk? The rotor would actually contact that on cornering too.....

Good find!

 

Yeah kinda weird i have 4600 miles on mine and rotors and pads look great, but i do light to light traffic, the only time i get to go fast is down an on ramp, the rest of the time i figure what is the purpose, i don't want to be the guy who floors it just to ride the guys ass in front of him then backing off and doing the same thing over and over, makes people look retarded

 

x2, looks like an ugly defect that needs some attention

 

Are you talking about my pictures? Because I was there, I took the pictures, the casting is absolutely touching the rotor. My pads are very much intact with plenty of material though.

 

the scoring krispy's pics show on the passenger side is exactly what mine looks like, except my drivers side is scored just as bad.

 

Gm needs to fix this problem. Way too many people are having this problem and if you aren't having this problem yet you will. Take note of when it happened. Mine started at around 6k, i'm at 13,000 now and its HORRIBLE. The dealer say its my fault. Theres no way theses pads and rotors should be in this condition at all. We need to do something about this now before we all have to buy new rotors and pads.

Gm needs to understand they gave us shitty pads and rotors!!!!!!!!!!

 

THEY ARENT SHITTY PADS OR ROTORS!!!!!!!!!!!!

The pads are aggressive, STFU about the pads everyone.

The wide grooves like Krispy has are caused by the rotor coming in contact with the caliper bracket when it moves. So yes the brackets have poor quality control. Not bad brackets....just bad finishing practices.

I youve got pad guides coming out of the bracket contacting the rotor, again not a fault with the pads or rotors, just the little stainless steel guides.

Take your cars in and request that these two items be inspected.

 

Had my car looked at and they're gonna fix the rear brakes under warranty, but between GM not having many of the pads in stock and everybody and their brother having the same brother as me, its going to be more than 2 weeks until i will get them put on

 

Tell them you want aftermarket pads, they cant MAKE you wait for parts, if they know its gonna be a while they can use other parts, **** you coulkd take it somewhere else have it done and bill GM

Read your owners manual