Brake Grinding Noise problems of the 2008 Chevrolet Cobalt

Since the car was purchased new, it has made occasional grinding noises from the rear brakes. The rear brakes have worn out so quick that this is the second time they are being replaced (three sets of rear brakes in under 50,000 miles). The replacements have not been covered under warranty because they are a "wear" item. This vehicle is the four-door "sport" model with the rear disc brakes and manual transmission. The problem is that the brakes wear very quick and the parking brake will no longer hold the vehicle on an incline. The emergency brake was adjusted by the dealership twice and they said there is nothing wrong with it, but I figured out what the problem is. The springs on the rear calipers that release the pads when the parking brake is disengaged are not strong enough to release the pads. Even when the parking brake is fully disengaged, the rear pads are clamped down on the rotors causing heat, premature wear, and more rolling resistance, leading to decreased parking brake function.

The rear brakes clunked and squeaked. Took it to the chevy dealership in November 2011. They replaced the pads and turned the rotors. Since the car was two months out of warranty the charge was 307. 40. Within 30 days the brakes started making the noise again but not as often or as loud. The sound has gotten progressively worse and more often. Instead of a squeak there is now an extremely loud grinding noise when stopping, particularly when there is moisture present. The brake pads still have plenty of material on them and the rotors are smooth. The noise is deafening in parking garages and can easily be heard 1/8th of a mile away. Stopping distance has increased and the vehicle does not feel safe.

Rear brake rotors have massive gouges casuing a grinding noise.

I own a 2008 chevy Cobalt ss. The rear brake pads were wearing out very quickly and damaging the rotors. First noticed a grinding noise on the rear brakes at 950 miles and now at 16,500 miles, I am sitting at the dealer service dept. Being told that my pads and rotors need to be replaced. The previous dealer ignored my requests to have this corrected before it got this bad. This dealer looked at it and they said that the car is not safe to drive until the brakes are replaced. So I am waiting to see if they will repair it or give me a loaner until it can be repaired. Updated 02/02/10 updated 02/05/jb.

At approximately 18,000 miles, my 2008 Chevrolet Cobalt ss had a grinding noise coming from the rear brakes. This noise was worse when I used the brakes. I drove the vehicle another 30 miles to my destination. Upon arrival, I noticed that I had lost about 50% of my braking power and that the grinding noise was much worse than when I first noticed it, 30 miles earlier. Of course, I replaced the brake pads, knowing that the noise they were making was caused by the pads wearing out and the metal grinding against the rotor. To my surprise, only the inside brake pads were worn to the metal, and the outer brake pads had just over 1/4 of an inch of pad left. I immediately called my local gm dealer and I was informed that there is a TSB (technical service bulletin) posted in their computer systems that says the problem is caused by the driver and that gm dealers are not to cover the rear brake problem. I know that this problem will occur in another 20,000 miles because there is something wrong with the calipers or entire brake system. The inside pads should not wear out faster than the front. They should also wear evenly. Another concern I have is the loss of braking power in only 30 miles from the earliest sign of a brake problem. I don't like the fact that the rear brakes, specifically the inside brake pads, are doing approximately 50% of the braking. Most of the braking should be done by the front brakes, which have well of 1/4 of an inch of brake pad left on the inside and outside pads.

Rear rotors failure. Massive scoring on rear brakes due to gm poor quality in brakes. Grinding noise when stopping.

Rear brakes on 2008 Chevrolet Cobalt ss worn significantly. Parking brake has very little tension. Grinding noise also comes from rear brakes.