Reported Jun 6, 1980147 vehicles affectedWAYNE CORPORATIONBuilt Oct 1, 1979 – Apr 1, 1980
The defect
In the process of assembly, which includes tapping into the chassis stop light switch circuit, a break occurred in the circuit that provides current to the emergency braking hydraulic pump motor. This causes the hydraulic service brake, hydraulic power assist back-up system to be inoperative when the ignition switch IS in the "off" position.
Vehicle description: school buses.system: service brakes; emergency braking; hydraulic pump motor.consequences of defect: this situation will normally occur when the vehicle isstopped or parked. The force required to be applied to the brake pedal to holdthe vehicle stationary will be abnormally high and may exceed the physicalstrength of most drivers. An accident could occur if the vehicle movesunexpectedly.note: when engine IS turned off and brakes are applied a warning signal of theproblem will be given by the brake lamp, brk elec mtr lamp, and the brakebuzzer. Until corrected, the parking brake should always be applied prior toturning the ignition switch off.