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
06-17-2009, 03:46 PM
#251
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600 miles on my car (300 mile drive from ohio to newyork to get the car from another dealer) so technically only 300 miles have been driven by me, and the rear brakes look phuuuuuuuucked! the tech at my work said something the 2nd day i had it...its getting towed to the dealer right now because my shift linkage is fucked as well (and no it isnt from abuse) i havent had a chance to beat on the car yet...**** my life
Nothing was fixed. To everyone that has had this replaced, please upload your service form because Chevrolet doesn't think this many people have this issue and that dealerships are actually fixing it.
Any part numbers for rear rotors?
06-18-2009, 12:06 AM
#252
Member
I'm picking up my car right now for the exact same issues and Chevrolet says "you're rear rotors are worn from racing but you front brakes are pristine." Dee Severn [Customer Assistance Center.
Nothing was fixed. To everyone that has had this replaced, please upload your service form because Chevrolet doesn't think this many people have this issue and that dealerships are actually fixing it.
Any part numbers for rear rotors?
Nothing was fixed. To everyone that has had this replaced, please upload your service form because Chevrolet doesn't think this many people have this issue and that dealerships are actually fixing it.
Any part numbers for rear rotors?
My case # with GM currently is 71728018797.
I hope others have written theirs down and post them here.
06-18-2009, 09:02 AM
#253
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CAC sucks ass. Good luck with that. They removed the reverse lockout and blamed by shift knob for the shifter linkage breaking. I've just been getting hosed from dealership to dealership.
06-18-2009, 12:49 PM
#254
ok guys...
so, in a nut shell, what do "we" believe the culprit is/are? i have read through all of the thread and have determined these possibilities:
1: lack of grease on the guide pins
2: bad pad compound (mixture - hard spots)
3: emergency brake out of adjustment
4: caliper bracket (molding partially coming in contact with rotor)
out of all the above possibilities and my experience as a mechanic, i believe the primary cause is the lack of grease on the guide pins. that would "aid" in the caliper "hanging up". add a harder compound (mixture) in the pad and grooves will begin...i have seen this before. add an out of adjustment parking brake (adjuster lever) does not release properly and leaves pad slightly in contact with the rotor...i have seen this also. why i have less faith in that the caliper is rubbing: the inconsistency of the grooves. everybody would have the same groove relationship on the rotor. i have compared a few of other cars with mine...
if it was abuse, it would affect ALL pads, not just one side and spot...da! so DO NOT allow the mechanic tell you anything different.
i am not saying i am correct, just adding my two cents and then some! i am bringing mine in tomorrow.
we will see...good luck to all
so, in a nut shell, what do "we" believe the culprit is/are? i have read through all of the thread and have determined these possibilities:
1: lack of grease on the guide pins
2: bad pad compound (mixture - hard spots)
3: emergency brake out of adjustment
4: caliper bracket (molding partially coming in contact with rotor)
out of all the above possibilities and my experience as a mechanic, i believe the primary cause is the lack of grease on the guide pins. that would "aid" in the caliper "hanging up". add a harder compound (mixture) in the pad and grooves will begin...i have seen this before. add an out of adjustment parking brake (adjuster lever) does not release properly and leaves pad slightly in contact with the rotor...i have seen this also. why i have less faith in that the caliper is rubbing: the inconsistency of the grooves. everybody would have the same groove relationship on the rotor. i have compared a few of other cars with mine...
if it was abuse, it would affect ALL pads, not just one side and spot...da! so DO NOT allow the mechanic tell you anything different.
i am not saying i am correct, just adding my two cents and then some! i am bringing mine in tomorrow.
we will see...good luck to allThe culprit I would say is brake pad compound.
Because:
1- wouldn't cause grooves and/or chewed rotors
2- WOULD cause grooves and /or chewed rotors (that's what I had, grinding noise too)
3- wouldn't cause grooves and/or chewed rotors, only fast brake pad wear or uneven
4- Could do it, but at least in my case, the calipers (or brackets) where never changed. Just machined rotors and new pads. If the calipers (or brackets) were the culprit the problem would repeat and I'd be right back in there. Mine look perfect still though.
That's what I think.
06-18-2009, 12:58 PM
#255
Senior Member
Grooving rotors isn't the only issue here, prematurely worn brake pads is part of the problem. Unlubricated caliper pins and an overly tight e-brake adjustment can contribute to faster pad wear, especially for the rear brakes. My 09 came from the factory w/o any lube on the caliper slide pins and the e-brake was very tight (both rear wheels had excessive drag).
06-18-2009, 02:32 PM
#257
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hey 'balters...
just came home from dealership...i was very, should we say..."stern" with them that is is unacceptable!! i said to them, "do not give me this is normal or i abused the car" period! i said "this is a track designed and tested car, brakes do not wear/groove on 2 out of 8 surfaces on the rotors even if they are driven hard"! never did the manager insinuate that it was either one...and the brakes he said (general manager)at this point i am in specs (GM specs for runout is .059) and GM will not cover for warranty. i told him do not tell me after i bring it in (lets say at 13,000) , once it is out of "specs" that it is a wear item!!! he said it is now documented and when the "time" comes for them to be turned (rotors and new pads put on), the warranty will cover it!! he even agreed that it is not wearing properly and for me to bring it back as soon as i believe that they may be "out of spec". i will ask my buddy to lend me his dial indicator and check the rotors when i rotate the tires at 7500...it is not IF the brakes will hit "out of spec", it will be when...i have 5,300 miles it now and i believe they will be shot by 10,000!!
good luck and don't wait. after the 12/12,000 they can say "wear item". even though we all know it is B.S. if the dealership wants your business and has any sense of "customer loyality" they will fix this problem...
blessings -
just came home from dealership...i was very, should we say..."stern" with them that is is unacceptable!! i said to them, "do not give me this is normal or i abused the car" period! i said "this is a track designed and tested car, brakes do not wear/groove on 2 out of 8 surfaces on the rotors even if they are driven hard"! never did the manager insinuate that it was either one...and the brakes he said (general manager)at this point i am in specs (GM specs for runout is .059) and GM will not cover for warranty. i told him do not tell me after i bring it in (lets say at 13,000) , once it is out of "specs" that it is a wear item!!! he said it is now documented and when the "time" comes for them to be turned (rotors and new pads put on), the warranty will cover it!! he even agreed that it is not wearing properly and for me to bring it back as soon as i believe that they may be "out of spec". i will ask my buddy to lend me his dial indicator and check the rotors when i rotate the tires at 7500...it is not IF the brakes will hit "out of spec", it will be when...i have 5,300 miles it now and i believe they will be shot by 10,000!!
good luck and don't wait. after the 12/12,000 they can say "wear item". even though we all know it is B.S. if the dealership wants your business and has any sense of "customer loyality" they will fix this problem...
blessings -
06-18-2009, 03:22 PM
#258
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I just got my car yesterday, after it spent 2 days at the dealership getting all 4 disk replaced, along with the sway-bar end-link and the steering column. When I inspected my car this morning, I had the pleasure to find these disk still installed on my car.
They also had the courtesy of damaging my side lip / skirt (whatever you call this), when they got the wheels off the front of the car to replace the front rotors.
My car currently has 18000 miles and both the front brakes and rear brakes needed replacement twice. 13000 of those miles are highway and they tried to deny the warranty work because of the high miles / claimed abuse. At this point I am seriously beginning to look into the legal actions I could take.
They also had the courtesy of damaging my side lip / skirt (whatever you call this), when they got the wheels off the front of the car to replace the front rotors.
My car currently has 18000 miles and both the front brakes and rear brakes needed replacement twice. 13000 of those miles are highway and they tried to deny the warranty work because of the high miles / claimed abuse. At this point I am seriously beginning to look into the legal actions I could take.
06-18-2009, 03:32 PM
#259
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Just noticed some people have posted some complaints about this rear brake problem here:
http://www.aboutautomobile.com/Compl...olet/Cobalt+SS
Maybe if everyone posted their problems here it would serve as some evidence that we could take to our dealers, since GM hasn't released a TSB yet.
http://www.aboutautomobile.com/Compl...olet/Cobalt+SS
Maybe if everyone posted their problems here it would serve as some evidence that we could take to our dealers, since GM hasn't released a TSB yet.
06-18-2009, 03:39 PM
#261
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That's good for you! You're lucky. I thought mine were good until I felt the inside rear rotors. They both have really bad grooves in them. I'm going to try and get them fixed under warranty....we'll see how that goes. I'm just over 16k miles now.
06-18-2009, 03:50 PM
#262
Senior Member
http://www.aboutautomobile.com/Compl...olet/Cobalt+SS
I think those are from the NHTSA, which is still good - keep them coming.
I think those are from the NHTSA, which is still good - keep them coming.
06-18-2009, 04:00 PM
#265
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Do you know for a fact that Chevy is instructing dealers not to fix the rotors? Or are you speculating based on a lot of people being denied warranty work? hmm....now that I think about it the dealers are probably just doing what GM tells them to do anyway. But that still doesn't explain why some people are able to get them fixed.
06-18-2009, 04:07 PM
#266
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Do you know for a fact that Chevy is instructing dealers not to fix the rotors? Or are you speculating based on a lot of people being denied warranty work? hmm....now that I think about it the dealers are probably just doing what GM tells them to do anyway. But that still doesn't explain why some people are able to get them fixed.
CAN EVERYONE THAT HAS HAD THIS FIXED POST YOUR SERVICE INVOICE? What are the details of what was done?
Last edited by dthomp2366; 06-18-2009 at 04:07 PM. Reason: Automerged Doublepost
06-18-2009, 04:22 PM
#267
Ima say no. Save your time and money and buy the parts and install them. Factory is pure garbage. Won't last 10k of highway miles.
Call CAC and ask for Dan Severn. He told two dealerships not to fix my car and won't believe other people with same problem had it fixed under warranty. Would you like his direct line?
CAN EVERYONE THAT HAS HAD THIS FIXED POST YOUR SERVICE INVOICE? What are the details of what was done?
Call CAC and ask for Dan Severn. He told two dealerships not to fix my car and won't believe other people with same problem had it fixed under warranty. Would you like his direct line?
CAN EVERYONE THAT HAS HAD THIS FIXED POST YOUR SERVICE INVOICE? What are the details of what was done?
Maybe everyone that has had this service post their work order number.
Also, you should print off this entire thread and take it to the dealer.
06-22-2009, 12:30 PM
#269
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Brought mine to dealership last month for oil change and asked them to check rear brakes due to excessive grooving on the rear rotors. I had approximately 9900 miles. Dealership says they are fine and still within specs.
Lately I've been hearing grinding from the rears, not as bad as full metal on metal, but not a good sound. Brought it in again today with a print out of this thread, with all the posts about being covered under warrenty highlighted. Car now has 11316 miles.
They resurfaced the rotors and tried to get pads. Stock pads were "majorly backordered". Said they were going to get some AC Delco pads for it. No problem. An hour goes by and they come get me to tell me the pads they got were the wrong ones, so they are just going to "sand and deglaze" the original pads and put it back together for me, and call me when they get the correct pads in.
It's still not 100% fixed, but it is better than it was, and it didn't cost me anything.
Hope that helps someone!
Lately I've been hearing grinding from the rears, not as bad as full metal on metal, but not a good sound. Brought it in again today with a print out of this thread, with all the posts about being covered under warrenty highlighted. Car now has 11316 miles.
They resurfaced the rotors and tried to get pads. Stock pads were "majorly backordered". Said they were going to get some AC Delco pads for it. No problem. An hour goes by and they come get me to tell me the pads they got were the wrong ones, so they are just going to "sand and deglaze" the original pads and put it back together for me, and call me when they get the correct pads in.
It's still not 100% fixed, but it is better than it was, and it didn't cost me anything.
Hope that helps someone!
06-22-2009, 01:30 PM
#271
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I don't have any way to scan it, but I could type what's on it if that helps.
PLUS,
I showed them the posts from here about the dealerships that DID cover it under warrenty and he said "yeah that's no problem anyway, you're still covered under your 3yr 36k anyways..."
PLUS,
I showed them the posts from here about the dealerships that DID cover it under warrenty and he said "yeah that's no problem anyway, you're still covered under your 3yr 36k anyways..."
Last edited by kidcrash603; 06-22-2009 at 01:30 PM. Reason: Automerged Doublepost
06-23-2009, 06:27 PM
#273
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So we checked mine out today cause the grinding noise has gotten worse i have 8900 miles on her. We found the left rear caliper holding the rotor the inside pad was gone chunks missing. we removed the park brake cable and that moved freely. We manually moved the park brake adjuster on the caliper and the piston was stuck wouldn't release like the right side. so we ordered a new left caliper, rotor, and pads for the rear. Thought this might help
06-23-2009, 09:51 PM
#274
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i got about 17k on mine n its grinding like really bad...bringing it tomorrow what do you thik they will do? it started a little pover amonth ago n the night i first heard the noise i called them n left a message...no call back now a month later its almost embarassing to drive it
06-23-2009, 10:46 PM
#275
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So we checked mine out today cause the grinding noise has gotten worse i have 8900 miles on her. We found the left rear caliper holding the rotor the inside pad was gone chunks missing. we removed the park brake cable and that moved freely. We manually moved the park brake adjuster on the caliper and the piston was stuck wouldn't release like the right side. so we ordered a new left caliper, rotor, and pads for the rear. Thought this might help