Rough braking that became worse to the point where vehicle control was questionable. GMC dealer advised that rotors on all 4 wheels needed to be replaced. Inspection of rotors indicated that significant amounts of metal had broken away from the brake pad contact area on the rotors. This caused the brake pads to then be applied over a washboard type surface which almost eliminated functionality. All pads and rotors were replaced on this GMC Jimmy vehicle which only has 38,000 miles. Dealer retained parts and billed $725.

- Rochester Hills, MI, USA

This vehicle at 11,000 miles one year ago went for state inspection and the rotors were so rusted that they could not be refaced so they were replaced under the general vehicle 3 yr 30,000 mile warranty. Then today at 27140 miles during state inspection the rotors were once again rusted so badly that they required replacement. Failure of these items could cause failure of braking system. Explanation from dealer without any testing was that this was due to the road salt. None of my other GM vehicles ( 1991 Jimmy with 169,000 miles, and a 1996 Grand Am with 159,000 miles) exhibit this symptom even though they are used on the on the same roads. There must be a problem with the specification for the metal in these rotors. This improper specification may lead to possible cracking of these rotors. I am requesting the old parts from the repair shop so that GM may inspect them. Being a quality engineer I know that GM will want these back to perform metallurgical analysis on the rotors and find the root cause of the rust.

- Renfrew, PA, USA