United States 00V162000
Blue Bird Body Company
The problem
VEHICLE DESCRIPTION: SCHOOL AND TRANSIT BUSES EQUIPPED WITH BENDIX AIR BRAKES. BENDIX CHANGED THE INTERNAL DESIGN OF THE QR1C RELAY VALVE BY ADDING A HOLE IN THE INTERNAL DIAPHRAGM. WHEN THE HOLE IN THE DIAPHRAGM ALIGNS WITH THE HOLE IN THE VALVE BODY, THE BRAKE APPLICATION TIME INCREASES.
Risk
UNDER CERTAIN CONDITIONS, SUCH AS PARKED ON AN INCLINE, DRIVER ACTIVATES THE PARKING BRAKE BUT REMOVES FOOT FROM THE THREADLE VALVE, THE BUS COULD ROLL BEFORE THE PARKING BRAKE IS FULLY ENGAGED.
What owners should do
DEALERS WILL REPLACE THE DIAPHRAGMS WITH HOLES WITH SOLID DIAPHRAGMS FOR THE QR1C VALVES.
Units 9687