Conventional Parking Brake problems of the 1999 GMC Sierra

I own a 1999 GMC Sierra 3 door truck. I was driving home when my brakes for some reason failed. I tried to use the emergency brake to stop the truck but it also failed. After pushing the truck home, I checked all the brakes and looked okay except for the rear right emergency brake lining. It was completely worn out to the metal. This was my first time using the emergency brake. Im not sure why the emergency brake gtt worn out if this was my first time using it.

While parking on a hill and without automatic transmission. Applied parking brake, and it didn't hold. Contacted dealer.

I have a 1999 new body style GMC Sierra 3 door truck. I am the only owner and driver of the vehicle. I attempted to use the emergency brake in 02/2002 and it did not prevent the truck from rolling. I have never used the emergency brake before to either stop the truck or hold it in place against a load. I took the truck in for other unrelated factory recall notices. I had the emergency brake checked. Both rear brake shoe where worn completely out and the drum on one side was beyond recovery. I had to buy new shoes and replace one rotor (approximately $450). Again, I have never used the emergency brake to stop the vehicle or hold it in place against a load. It has not been used. This is a serious safety problem. I talked to a GMC mechanic and several truck owners and they have had the same problem. The mechanic said he has replaced several emergency brake systems with the owner stating the same thing I have concerning usage. Some of these vehicles had less than 30k miles on them. My brother has a 2000 chev. Truck and the same problem. A brake specialty repair center told him the same thing the GMC mechanic told me. The emergency brake system has a serious design flaw. It wears out without warning to the owner. I wrote GMC customer service and they dismissed my concern without firm explanation after several letters. Please investigate this concern. I do not think this is an isolated occurance.

Emergency parking brake is inoperative. Dealer notified. Feel free to provide any further information.