One problem related to service brakes has been reported for the 1999 GMC C1500. The most recently reported issues are listed below.
While driving on public 4 lane highway and coming to a yellow light I applied the brake pedal and the pedal instantly went to the floor. I tried to pump the pedal in a panic and still had no effect on stopping the truck. I downshift'ed in to 1st gear manually to use engine braking and slammed my emergency to the floor. The truck was unable to complete the stop in which in had more than 300 ft to do so and I preceded through what had become a red light. This incident happened very late at night so thankfully there were no other vehicle going through the intersection. I had a friend escort me the mile left to my house via his truck and tow strap and my emergency brake as my only brake not to hit the back of his truck. Now upon visual inspection of all my brake and fuel lines they are completely rusted at multiple spots throughout the frame channel and rear axle area. The burst location happened just at the back or drivers door edge to the front of the l/r wheel.