What was found
FUEL OVERRIDE/JETTISON PUMP PART NR 60-72101 DASH 2 RECOVERED FROM THE NR 2 MAIN FUEL TANK (AFT POSITION) OF ACFT 8407 WAS FOUND TO EXHIBIT EXCESSIVE IMPELLER END-PLAY AND GOUGING OF THE IMPELLER UNIT WITH THE INLET ADAPTER. TESTING OF THE PUMP BY THE VENDOR SHOWED THAT THE AXIAL THRUST-BALANCING MECHANISM FAILED. THE THRUST WASHER/BEARING IS SUSPECTED TO HAVE BEEN MANUFACTURED INCORRECTLY. ROOT CAUSE OF FAILURE HAS NOT BEEN IDENTIFIED AS YET.