Brake Disc Caliper problems of the 2001 GMC Sierra 1500

While slowing down at my neighborhood elementary school I applied the brakes at the stop sign. The brake pedal began to pulse. I drove around the block to my house. Upon investigation, a 12" section of the inside of my left rear brake rotor broke off. When the rotor continued to turn, the remaining section of the brake rotor caught the caliper piston and sheared it off. Luckily, I was only driving at 18 mph. If I had been on the highway driving 55-65 mph, the loss of braking would have been catastrophic. The piece that broke off was covered with rust on the inside - the side manufactured with cooling openings which are located between the inside and outside of the brake rotor.

We own a 2001 GMC Sierra 1500 pickup truck with around 55k miles. Last Dec 2010 the brakes failed when applying pressure. We thought the problem was one of the rear calipers; however, upon further diagnosis, it was determined the brakes lines had rusted and subsequently burst/ruptured during a brake application. Fortunately, the vehicle was close to home when the brakes failed and we managed to get our truck home without incident. We left our truck parked over the winter to deal with the issue when the weather would be more cooperative for having our vehicle towed to a repair shop. I contacted gm early March 2011 regarding our problem and gm said a gm authorized dealer had to diagnosis the problem. We had our pickup towed to a local GMC dealer and the dealer?s service dept charged us $98 to inspect our vehicle. The dealer reported back to gm that the corrosion was caused by lack of maintenance. The dealers estimate was $4,657 to replace the brake lines and perform other maintenance work caused by the lines rupturing. If the "ebcm for the anti-lock brakes did not have to be replaced, then the dealer?s estimated repair bill was reduced to $3,316. I informed gm that I've owned 10 or so vehicles in my lifetime and never had any brake lines corrode/rupture during a brake application nor did I have to have preventative maintenance performed on the brake lines to prevent them from corroding. Other owners of gm pickups/suvs have also filed complaints on NHTSA?s website for this same brake line failure problem due to corrosion. A preliminary evaluation was opened by NHTSA to determine the frequency, scope and safety consequences of the alleged defect in gm pickups/suvs manufactured during 1999 to 2003. The investigation number is "pe 10-010" dated 30 March 2010. The subject is "brake line failure due to corrosion". This investigation was opened March 2010 and I cannot locate any updates on the NHTSA website. Updated 05/19/11.