BRAKE AIR LINES WERE INCORRECTLY INSTALLED. THE BRAKE AIR LINES FROM THE BULKHEAD FITTINGS TO A TWO-WAY VALVE AND TO A RELAY VALVE WHICH FEEDS THE PARK BRAKE AND SERVICE BRAKES WERE INADVERTENTLY REVERSED DURING INSTALLATION. CONSEQUENCE OF DEFECT: THIS CONDITION ALLOWS THE PARKING BRAKE TO FUNCTION NORMALLY, BUT WHEN THE SERVICE BRAKES ARE APPLIED AIR IS DIRECTED TO THE PARKING BRAKE DIAPHRAGMS AND NOT TO THE SERVICE BRAKES. THIS WILL SUBSTANTIALLY REDUCE THE STOPPING CAPABILITY OF THE SERVICE BRAKES. ALSO, IF THE PARKING BRAKES ARE APPLIED, THEY MAY BE DIFFICULT TO RELEASE.
INSPECT AND MAKE PROPER INSTALLATION OF THE AIR BRAKE LINES.
SYSTEM: BRAKES/AIR LINES. VEHICLE DESCRIPTION: MODEL 96A2 COACH BUS.