One problem related to service brakes has been reported for the 2002 Chevrolet Express. The most recently reported issues are listed below.
2002 chevy 2500 Express van. Failure of power booster, lost both brake power as well as steering power. Almost impossible to control car. Replaced once, failed again 6 months later. Replaced again. Failed again this year. I am now on my forth power booster, failure is very dangerous as you lose both steering and brakes at same time.