One problem related to brake hoses, lines/piping, and fittings has been reported for the 1998 GMC Jimmy. The most recently reported issues are listed below.
While going downhill and applying the brakes, the pedal went to the floor and there was no braking ability. Consumer used emergency brakes and went into a ditch to avoid a crash. Problem believed to be caused by part of the brake hose line missing because it hit the exhaust manifold and melted.