AIR LINE DETACHING FROM DASH

What NHTSA is examining

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…

Vehicles under investigation