One problem related to brake master cylinder has been reported for the 2000 Chevrolet K2500. The most recently reported issues are listed below.
For the time in 4 months, my 2000 Chevrolet K2500hd full sized pickup truck has experienced brake failure due to rust-through of a brake line. The first failure point was located near the right front wheel in the vicinity of the metal line to rubber hose connection, in the exact location where the metal line runs between the frame and the electrical connector for the antilock system's wiring to the right-front wheel sensor. Today's failure is located in the engine compartment directly under the master cylinder. The actual leak is in a section of line that is not obscured by any mounting points. It is out in the open and fully visible when looking into the engine compartment while standing in front of the vehicle. Several other sections of brake line appear have major rust issues also. This truck has 45,454 miles on it. The original brake master cylinder failed at 26,xxx miles. The vehicle's warranty had expired, so I was responsible for this repair. I have noticed the brake fluid in the reservoir of this vehicle has a history of turning to a dark color within a short period after a brake fluid flush, even after the replacement master cylinder was installed. I have never been satisfied with the stopping power of the brakes on this truck. I am the original owner, and since the truck was new I always felt the brakes had a very "spongy" feel. Even when new there were a few occasions when I experienced am I going to be able to stop scares. I must now have the truck towed to a repair facility, to have the entire system of brake lines inspected and replaced as necessary. Obviously the truck is not safe to drive until this is done.