THE RETAINING PIN FOR THE BRAKE CONTROL KNOB HAS BEEN MISALIGNED (OFF THE CENTER LINE OF THE VALVE PLUNGER HOLE). THIS CAUSES THE KNOB TO BE OVERSTRESSED AT THE RETAINING PIN HOLE AREA CAUSING IT TO SEPARATE FROM THE VALVE.
THE HOLES WILL BE RETOOLED TO PROVIDE CORRECT ALIGNMENT AND PLASTIC KNOBS WILL BE REPLACED BY KNOBS OF STRONGER MATERIAL HAVING METAL REINFORCEMENTS.
VEHICLE DESCRIPTION: TRUCKS EQUIPPED WITH BRAKE CONTROL KNOBS.SYSTEM: SERVICE BRAKES; KNOB RETAINING PIN.CONSEQUENCES OF DEFECT: WITH THE KNOB BROKEN OFF, THE CONTROL VALVE WOULDBECOME DIFFICULT OR IMPOSSIBLE TO OPERATE. ONE OR A COMBINATION OF BRAKEAPPLICATIONS WOULD NOT BE POSSIBLE AND THE VEHICLE COULD BE PARKED IN AN UNSAFECONDITION. AN ACCIDENT AND PERSONAL INJURY COULD RESULT.