help, premature brake wear

Post by **TireSmoker** » Tue Mar 30, 2010 11:18 am

Guys,

I took my Cobalt SS into the dealer for a problem with the rear brakes. The rotors were all scored up and they told me the pads were worn out (2mm of material left). Car has 18,500 miles.

The dealer is trying to tell me that this is normal wear. I argued saying that the fronts don't look anything like that, they do the majority of the braking, and that the rears should not be this worn out at this mileage.

Any advice on how I should proceed?

-Dave

wxo · Post by **wxo** » Tue Mar 30, 2010 5:30 pm

Dave, I searched TSBs for your car and didn't see known problems concerning rear brake wear.

You can fight it and get all aggravated or you can just fix it yourself using quality components.

GMJohnny · Post by **GMJohnny** » Tue Mar 30, 2010 6:35 pm

If only the rears are turfed up, perhaps the e-brake has hung up in the past, or is still doing it occaisionally. I have never had a front wheel drive car that needed rears before it needed fronts. My experience has been to put rears on every other time I put fronts on. I have also found that the cheapest brake shoes I can get my hands on last pretty well, and do minimal damage to the rotors. I have also found that the rotors are so cheap that turning them is not cost effective either. I think I did the regal fronts and backs, rotors and all for around $100.00. ( You could always disconnect the rears until the fronts are worn out, then do them all at the same time!!! )

GM

MostMint · Post by **MostMint** » Tue Mar 30, 2010 7:09 pm

Did you mention that it was at mid-Ohio?

My SS brakes were shot at 30k. The rears may have less material than the fronts.

Basement Paul · Post by **Basement Paul** » Tue Mar 30, 2010 9:07 pm

On disk brake cars at both the VW and Lexus dealers I worked at, we did replace rear brake pads more rapidly then the fronts. The rear brakes are much smaller, and they also see more debris than the fronts as you drive down the road, especially here where the rotors will get rusty just sitting overnight or even while you sit at work for nine hours.
I'd say you're looking at a pretty normal condition.

-BP

wxo · Post by **wxo** » Wed Mar 31, 2010 6:34 am

It must be a northern Ohio thing. I rarely have to work on rear disk brakes on the cars I've owned. I suppose the weather and salt have a lot to do with it.

GMJohnny · Post by **GMJohnny** » Wed Mar 31, 2010 9:28 am

WXO, based on your avatar, you use a line lock to save your rear brake shoes!!

Post by **TireSmoker** » Wed Mar 31, 2010 10:22 am

Basement Paul wrote:On disk brake cars at both the VW and Lexus dealers I worked at, we did replace rear brake pads more rapidly then the fronts. The rear brakes are much smaller, and they also see more debris than the fronts as you drive down the road, especially here where the rotors will get rusty just sitting overnight or even while you sit at work for nine hours.
I'd say you're looking at a pretty normal condition.

-BP

I believe you, but at the current rate, that means I'm gonna go through 5 sets of rear brakes by the time I hit 100k. That just seems.. excessive.

-Dave

MostMint · Post by **MostMint** » Wed Mar 31, 2010 10:43 am

Have you thought about trying another dealer?

Post by **TireSmoker** » Wed Mar 31, 2010 12:45 pm

I already had them do the work. $230-ish. (I havent picked it up yet) I've never, ever heard of rear brakes lasting less than 40k miles, so in my mind, this should've been a warranty repair and I feel burned at having to pay for this.

With what Paul said, I guess I feel ever so slightly better, but to have the service manager tell me that 18k was normal wear and tear for rear brakes, that pegged by BS meter.

Call me crazy, but a set of brakes should last two years. I commute from Chesterland to either downtown or Independence, which is 80% freeway driving. I don't do much stop-n-go city driving.

-Dave

wxo · Post by **wxo** » Wed Mar 31, 2010 5:30 pm

GMJohnny wrote:WXO, based on your avatar, you use a line lock to save your rear brake shoes!!

Save shoes. Burn up tires!

Basement Paul · Post by **Basement Paul** » Wed Mar 31, 2010 10:18 pm

Normal driving might be easy on brakes, but slowing down from over 100mph, probably puts a hurt on them quickly. The car has been to the track several times, plus the 120mph shots down the freeway aren't helping much either. I'm guessing the second set of pads will last longer as the novelty of the car has probably worn off at least a little.
If those don't last, just get some autozone pads and change them yourself for $40.

-BP

markss327 · Post by **markss327** » Thu Apr 01, 2010 8:45 am

My neighbor across the street, had a Nissan Altima, and she tore up the rear rotors with less than 20k miles. It was $250ish from the dealership (stealership) too.
It was a leased car, and soon dumped for an Accord.

I don't get it. Colleen's 2002 minivan with 78k, is on it's second set of brakes. Normal for the age and mileage. The OEM set lasted untill 58k.
I did brakes on the Immpy at 43k, (about 28k ago). The last tire rotation shows normal wear on both the fronts and rears.
On both cars, the e-brake is a tiny drum set-up, inside the disc 'hat'. I'm not buying the e-brake hanging up train of thought.

Unless I'm mistaken, braking proportioning is 70-30. Front-rear respectively. So, the fronts, even being larger in swept area, should wear out sooner than the rears.

Even if the brakes have been romped on, the fronts still get the abuse.

My only consensus - the OEM material used on the rear pads (and/or rotors), is sub par.

MostMint · Post by **MostMint** » Thu Apr 01, 2010 9:36 am

If other Cobalt SS's are not having this problem, it's probably because most of them don't get a couple hours of hard racing with heavy braking! Maybe the rears don't cool as well as the fronts so under racing conditions they heat up more and therefore wear more.

IIRC you said the tires took a beating during that adventure. I have to believe the brakes did also.

If you ever go to the road course again, you might want to measure brakes for wear before and after.

Post by **TireSmoker** » Thu Apr 01, 2010 11:53 am

Other Cobalt SS's are having issues. Many people have had the scoring on the rotors. I think others have replaced their pads before me, based on a thread I saw on cobaltss.net

However hard I've driven this car, brakes should absolutely not wear out before the tires. And the tires have seen way more abuse than the brakes. The tires, while well worn, still have a few thousand miles left on them.

I would've been happy if they had met me half-way, like covering the labor and I pay for parts, or something. Brakes are a wear item, I get that. But they should've lasted a noticeably longer, IMO.

-Dave