NHTSA Investigation PE07050

AIR LINE DETACHING FROM DASH

THIS INVESTIGATION WAS OPENED AFTER ODI RECEIVED NOTIFICATION FROM TWO FLEETS (TOTALING SEVEN COMPLAINTS) ALLEGING THE AIR LINES CONNECTING TO THE DASH AIR GAUGE WERE LEAKING AIR AND SETTING OFF THE LOW PRESSURE AIR BUZZER. DURING THE COURSE OF THIS INVESTIGATION, ODI INTERVIEWED THE INVOLVED FLEETS, CONDUCTED FIELD TRIPS TO EXAMINE SIMILAR BUSES, VISITED DEALERS AND REVIEWED DATA FURNISHED BY BLUE BIRD IN RESPONSE TO AN INFORMATION REQUEST.WHILE BIRD BIRD WAS UNABLE TO DETERMINE A DEFINITIVE CAUSE FOR THE REPORTED FAILURES, THEY BELIEVE THE LOWNUMBER OF COMPLAINTS INDICATES AN ANOMALY AND THE LEAKS MAY HAVE BEEN CAUSED BY THE UNINTENTIONAL POSITIONING OF THE HOSE DURING DASH INSTALLATION.BLUE BIRD THEORIZES THAT AS THE 1/4 DASH GAUGE AIR LINE TUBING WAS INSTALLED BEHIND THE DASH, THE TUBING ENTERING THE PUSH-IN QUICK DISCONNECT FITTINGMAY HAVE BEEN POSITIONED AT AN ANGLE PUTTING STRESS ON THE PLASTIC MOVABLE PART OF THE FITTING. OVER TIME THIS STRESS MAY HAVE CAUSED THE PLASTIC PART OF THE FITTING TO DETERIORATE,RESULTING IN AN AIR LEAK.BASED ON THE RESULTS OF AN AIR BRAKE SYSTEM TEST CONDUCTED BY BLUE BIRD, COMPLETE DISCONNECTION OF THE ? AIR LINE AT THE DASH AIR GAUGE DOES NOT DEPLETE THE BRAKE AIR SYSTEM TO THE POINT WHERE THE BRAKES WILL NOT OPERATE AS DESIGNED. THE TEST SHOWED THAT EVEN WITH THE AIR LINE DISCONNECTED, NORMAL OPERATION OF THE BUS WILL CONTINUE TO CHARGE THE AIR SYSTEM RESERVOIR, ALLOWING FOR SAFE OPERATION UNTIL THE BUS CAN BE CHECKED. NEVERTHELESS, ALTHOUGH BLUE BIRD'S TEST DATA AND CUSTOMER INFORMATION CONFIRMS THERE IS NO LOSS OF BRAKES WHEN THE DASH AIR GAUGE LINES LEAK OR BECOME DISCONNECTED, BLUE BIRD INTENDS TO DEVELOP A SERVICE BULLETIN TO INSPECT THIS AIR LINE CONNECTION. THE SERVICE BULLETIN WILL BE SENT TO OWNERS OF ALL 2006 AND 2007 MODEL YEAR BLUE BIRD ALL AMERICAN SCHOOL BUSES.BASED ON THIS INFORMATION, A SAFETY RELATED DEFECT TREND DOES NOT EXIST AT THIS TIME AND FURTHER USE OF AGENCY RESOURCES IS NOT WARRANTED. THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY DEFECT EXISTS.THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES. THIS INVESTIGATION IS CLOSED.

An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.