Defect summary
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.
Consequence
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.
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.
Notes
SYSTEM: BRAKES.VEHICLE DESCRIPTION: 60 FOOT ARTICULATED BUSES.
Source: NHTSA ODI recalls file, campaign 91V205000. Text as published by NHTSA.