One problem related to brake master cylinder has been reported for the 2001 GMC C2500. The most recently reported issues are listed below.
2001 GMC sierra 2500 hd diesel with allison trans, while on vacation 800 miles away lost all brakes (front and rear) nearly killing people. Found brake line bust at the fuel tank (which was full) excessive corrosion on all brake lines and under carriage of this truck less than 50k miles. This is the third time first had all rotors fail at 20k, dealer reluctantly replaced only by forcing the issue (under warranty) then at 36k line bust at master cylinder (front and rear) corrosion, $500 , then the line after that one to the proportioning valve another 500 to fix, the front hubs replaced two times at 300 each bad wheel bearings and corroded hubs, now rear line at the tank area, truck has 49k miles never in salt/snow, washed reg. Yet underside looks like a junker. This truck has been a disaster since day one! antilock brakes 3x, rotors 2x calipers once, brake lines 3 x and this is before 40k miles!!! , only thing that saved us from the mortuary was fast acting on my part , and throwing it in one on the trans, which I suspect is next. Who do you have to run over before there is a recall? gm is junk! I suggest all gm truck owner check under for corrosion as they use crap material in making their trucks. . Heavy duty my [xxx] ! information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).