SERVICE BRAKES, AIR:ANTILOCK
Nov 22, 1991
171 units potentially affected
The defect: THE EXISTING INTERLOCK AIR BRAKE SYSTEM MUST GET ITS AIR SUPPLY DIRECTLY FROM THE PARKING BRAKE AIR SUPPLY CIRCUIT. SHOULD A COMPONENT FAILURE OCCUR IN THE INTERLOCK AIR SYSTEM, IT WILL DEPLETE THE AIR SUPPLY FROM THE PARKING BRAKE CIRCUIT.
The risk: DEPLETION OF AIR SUPPLY FROM THE PARKING BRAKE CIRCUITWOULD ALLOW THE BUS TO ROLL WITH THE PARKING BRAKE APPLIED. THIS COULDRESULT IN A VEHICLE ACCIDENT.
The remedy: RELOCATE THE AIR SUPPLY LINE FOR THE INTERLOCK SYSTEM SO THAT THE AIR SUPPLY COMES FROM THE PARKING BRAKE CIRCUIT TO ENSURE THAT WHEN THE PARKING BRAKE IS APPLIED, THE PARKING BRAKE CANNOT BE DISENGAGED OR OVERRIDDEN BY COMPONENT FAILURES.
VOLVO GM HEAVY TRUCK CORPView on NHTSA.gov