What was found
THE CREW DEPARTED FROM KSEZ ON A ROUTINE PASSENGER FLIGHT TO KPAE. DURING CRUISE AT 40,000 FEET, THE CREW NOTED FUEL COMING FROM THE LEFT-HAND WING. BASED ON RECOMMENDATIONS BY PILATUS, TECHNICIANS REPLACED THE FLOAT VALVE PN ON/OFF: 963.82.21.320; SN:F13 WITH NEW SN:0432, IAW AMM PC24-A-E28-20-0011-00A-520A-A AND PC24-A-E28-20-0011-00A-720A-A. COMPLETED FLOAT VALVE OPERATIONS CHECK IAW PC24-A-E28-20-0011-00A-320A-A. NO DEFECTS WERE NOTED. PILATUS HIGHLIGHTED SERVICE LETTER 059 AS A FIX TO THIS ISSUE, HOWEVER, THE SUPERSEDING PART NUMBER 963.82.21.323 WAS NOT AVAILABLE. THE REMOVED PART SHOWED SIGNS OF A WORN FLOAT HINGE AND A FAILED TEFLON SEAL.