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
Senior Member
Joined: 11-22-05
Posts: 1,421
Likes: 0
From: Toronto
So what are some updates? Dealers are telling some people that it's normal, telling people it was abusive driving and some people are getting the brakes replaced under warranty. I've read all the pages about this issue from the other members but I would like some insight on how to properly word the issue to my service department. I have general knowledge about cars but no skill in arguing back and forth about something I don't know that much about (this brake situation).
I have 11600 KMS on the car (~7200miles) and the issue exists on the inside of the rear brakes.
I have 11600 KMS on the car (~7200miles) and the issue exists on the inside of the rear brakes.
So what are some updates? Dealers are telling some people that it's normal, telling people it was abusive driving and some people are getting the brakes replaced under warranty. I've read all the pages about this issue from the other members but I would like some insight on how to properly word the issue to my service department. I have general knowledge about cars but no skill in arguing back and forth about something I don't know that much about (this brake situation).
I have 11600 KMS on the car (~7200miles) and the issue exists on the inside of the rear brakes.
I have 11600 KMS on the car (~7200miles) and the issue exists on the inside of the rear brakes.
Tell them accurately what noises it makes and wehn, and what you noticed on the brakes.
The reason people are having different results at the dealer is because people are having different issues.
Member
Joined: 11-02-08
Posts: 213
Likes: 0
From: Quebec city, Canada
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...
I have 3750k on the car and the rear brakes are already worn out under normal driving conditions.
It ain't normal, period.
I'm having them checked next monday and they better do the honorable thing.
Senior Member
Joined: 11-22-05
Posts: 1,421
Likes: 0
From: Toronto
Took my car to dealer. They said there was a defect in the rear pads where it "wasn't finished properly". I told them to not mistake this for a freak accident because there have been many cases already in the states. They ordered me new pads and rotors. Rotors came the next day and now I'm waiting for the pads.
Service consultant told me that it's possible that the same defected pads could come because there is no bulletin for the problem.
Should I just go grab a set of aftermarket pads to go with these new rotors? Would the dealer instal them? Should I go with the stock ones when they come? Any thoughts?
Service consultant told me that it's possible that the same defected pads could come because there is no bulletin for the problem.
Should I just go grab a set of aftermarket pads to go with these new rotors? Would the dealer instal them? Should I go with the stock ones when they come? Any thoughts?
This morning I finished deburring the rear caliper brackets that was causing the scoring of the rotors.
The inner pads are wearing slightly faster than the outer ones but with 8000 miles on the Balt, some brake wear is to be expected.
The scoring hadn't gotten any worse in the last two weeks since I looked at it and the pads may have machined a bit of it away. Not serious enough to replace the rotors in my case anyway. The grooves were less than .015 - .020 as far as I can tell and only about .050 wide.
I could see the shiny spot on the driver side bracket where it was rubbing the rotor, but the passenger side must have worn down enough already to give it enough clearance.
A few seconds with a die grinder and all is well.
Thanks to all the original pics posted so I had no trouble finding the cause.
Maven, I PM'd you the measurement you asked for on the distance from the back of the rotor to the front of the wheel hub surface.
It's 62 mm as far as I can tell by my old eye doing the measuring. Hope that helps until we can find some rotor specs.
The inner pads are wearing slightly faster than the outer ones but with 8000 miles on the Balt, some brake wear is to be expected.
The scoring hadn't gotten any worse in the last two weeks since I looked at it and the pads may have machined a bit of it away. Not serious enough to replace the rotors in my case anyway. The grooves were less than .015 - .020 as far as I can tell and only about .050 wide.
I could see the shiny spot on the driver side bracket where it was rubbing the rotor, but the passenger side must have worn down enough already to give it enough clearance.
A few seconds with a die grinder and all is well.
Thanks to all the original pics posted so I had no trouble finding the cause.
Maven, I PM'd you the measurement you asked for on the distance from the back of the rotor to the front of the wheel hub surface.
It's 62 mm as far as I can tell by my old eye doing the measuring. Hope that helps until we can find some rotor specs.
New Member
Joined: 08-08-08
Posts: 86
Likes: 0
From: Akron, Ohio
I'm glad this issue has been figured out and resolved. 
But, I'm sick of having to read through a bunch of childish bickering on who is right about what.
If your gonna contribute to the discussion then make sure you not being an ass. Some of us are new to this, but not retarded, and want to hear what the more experienced guys have to say.
As long it doesn't come in the form of " I AM THE HIGH AND MIGHTY ALL KNOWING!" class dismissed.
But, I'm sick of having to read through a bunch of childish bickering on who is right about what.
If your gonna contribute to the discussion then make sure you not being an ass. Some of us are new to this, but not retarded, and want to hear what the more experienced guys have to say.
As long it doesn't come in the form of " I AM THE HIGH AND MIGHTY ALL KNOWING!" class dismissed.
I got your PM, just didnt respond yet. Ill have to keep looking, the 62mm height is going to be tough to accomodate. The Brembo rotors I was thinking might work, WONT. Ill keep digging.
Far as I can say you dont even need to see the rear rotors to tell if you have the problem.
my car is only at 4000 K and I have huge grooves ont he rear inside rotor. the outside and all the front are still smooth(ish)
A rotor should not feel that bad with huge grooves after only 4000K of normal driving.
I will be bringing it to the deal this week with pictures of the problem.
my car is only at 4000 K and I have huge grooves ont he rear inside rotor. the outside and all the front are still smooth(ish)
A rotor should not feel that bad with huge grooves after only 4000K of normal driving.
I will be bringing it to the deal this week with pictures of the problem.
Senior Member
Joined: 07-03-08
Posts: 580
Likes: 0
From: NJ
so i think my condition is a little different the the OP's...i just pulled the wheel and took some pics...its only doing it on the left rear side on the inside of the rotor...im getting the feeling its just the pads any ideass??.
pads are out in this pic..
pads are out in this pic..
Senior Member
Joined: 07-25-08
Posts: 12,450
Likes: 6
From: Florida
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?
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?
My 09 SS/TC sedan only has 150 miles on it right now (only about a week old), but after reading this and a few other threads on the subject I pulled the rear wheels off and took a look around. Everything looked fine (as expected with the minimal mileage) - inner surface of the rotors felt smooth and there was no casting flash that I noticed to be contacting the rotor on either side. With a feeler gage it looked like there was a consistent minimum gap between the caliper mounting bracket and the rotor of ~ 0.050" on the inboard side (this was true for pax and driver sides and below/above the pad). Outboard side had more clearance, but I didn't measure it exactly. My guess is that it was closer to 0.080". I did pull the guide pins and all four were dry as a bone, though, so I lubed them up. I'll post up some pics tomorrow if anyone's interested.
Here are a few of the pics that I took. Unfortunately the batteries in my camera died right in the middle of this so I didn't get many shots. Not much to see anyway, really.
View looking up at the inboard side of the passenger side caliper.
Same view with an 0.035" feeler gage inserted between the mounting bracket and the rotor. Hard to see in this view, but there is clearance. Gap was about 0.050" on both rear caliper brackets above and below the inboard pad in each case.
Top view of the driver side caliper. This one shows the gap reasonably well.
Guide pins as they came out (7mm allen key for these BTW).
Now with some lube.
View looking up at the inboard side of the passenger side caliper.
Same view with an 0.035" feeler gage inserted between the mounting bracket and the rotor. Hard to see in this view, but there is clearance. Gap was about 0.050" on both rear caliper brackets above and below the inboard pad in each case.
Top view of the driver side caliper. This one shows the gap reasonably well.
Guide pins as they came out (7mm allen key for these BTW).
Now with some lube.
Member
Joined: 06-03-05
Posts: 281
Likes: 0
From: Nazareth,PA
Just took my 09 TC to the dealer for my brakes squealing. they didnt hear anything about the problem so the guy looked it up in the computer. And it had a note saying telling them not to fix or touch the brakes that it is normal for it to squeal.
"Inform the customer that this is a normal characteristic of the high performance brake system"
"DO NOT repair or replace the rotors or brakes"
so i am alittle pissed off right now!! i paid around 24,000 for this car to have squealing brakes what F*ck!
"Inform the customer that this is a normal characteristic of the high performance brake system"
"DO NOT repair or replace the rotors or brakes"
so i am alittle pissed off right now!! i paid around 24,000 for this car to have squealing brakes what F*ck!
New Member
Joined: 08-08-08
Posts: 86
Likes: 0
From: Akron, Ohio
Dude, you bought a 24k car with some really powerful brakes. Equipped with pads that produce massive amounts of friction. If you would rather have quiet brakes with less stopping power and switch them.
Squeaks, but stops on a dime.
or
Quiet, and half the stopping power.
hmm, decisions decisions.
Squeaks, but stops on a dime.
or
Quiet, and half the stopping power.
hmm, decisions decisions.
Member
Joined: 06-11-08
Posts: 237
Likes: 0
From: Buffalo NY
GM rotors are terrible to begin with the last car i had the rotors were crap in 1 year. Once i replaced pads and rotors from napa where i work they were working great. I had on my g5 GT that i traded in, drilled and slotted rotors and adaptive one brake pads all from napa where i work.
Senior Member
Joined: 05-18-05
Posts: 1,070
Likes: 1
From: Boston & SoCal
Update:
Pulled up next to a concrete barrier coming into a gated area last night and heard some nice metal contact from the rear while braking. Car has just under 28k miles, nearly all highway, and the rear pads were starting to look pretty worn but still serviceable as of the last tire rotation a few thousand miles ago. I have to crawl under the car in the morning but it sounds like it will be time for some new pads and rotors. Never thought the stock Conti's would outlast the brakes.
Pulled up next to a concrete barrier coming into a gated area last night and heard some nice metal contact from the rear while braking. Car has just under 28k miles, nearly all highway, and the rear pads were starting to look pretty worn but still serviceable as of the last tire rotation a few thousand miles ago. I have to crawl under the car in the morning but it sounds like it will be time for some new pads and rotors. Never thought the stock Conti's would outlast the brakes.