Two problems related to brake master cylinder have been reported for the 2002 Chevrolet 1500. The most recently reported issues are listed below.
Drove to milan, mi from ypsilanti, mi. To look in on sister in law who is incapacitated due to broken femur from fall. Brakes felt mushy as I slowed to enter her driveway. After entering the driveway at low speed I applied brakes and pedal went to floor. Tried pumping brakes with no result. Threw shifter into reverse to keep from plowing into sister in laws vehicle. If this had happened earlier on the busy road leading into town I would have surely had an accident. Found brake lines badly rusted and both lines leaking that run from master cylinder to antilock module mounted to frame under drivers area. It is ridiculous that these two safety sensitive lines are made of un protected steel as opposed to copper nickel and are run out of the protected under hood area to the high corrosion prone underbody to meet the inappropriately placed antilock module. Two years prior to my purchase of this truck gm heavily advertised the rust resistant galvanized panels they were using in their trucks. I have since found out that they quietly removed this rust protection. I have ordered new break lines to totally replace all metal lines on this, my last chevy truck. I can only wonder how many fatalities have resulted from this often referenced condition. The difficulty will be in ever proving the cause and affect (effect) of these accidents since they will be so devastating in nature, the driver will probably be killed and not be able to testify about the true cause and almost all gm trucks of this vintage (especially in the rust belt states) will have break lines so rusted that they will crumble in almost any accident. My experience shows that the unfortunate driver won't always have "some" breaking ability left on a line failure.
While backing my truck out of the garage I lost my brakes due to pedal going to floor and loosing brake fluid. I was able to get it to stop with emergency brake. Upon further investigation I noticed all brake lines that route on outside of frame between master cylinder and abs module were rusted badly and were wet with brake fluid.