What was found
DURING SINGLE POINT REFUELING, FUEL LEAKED OUT OF THE LT NACA VENT. FOUND THE LT VENT FLOAT VALVE FAILED CLOSED. THE SCREW ATTACHING THE VALVE FLAP TO THE FLOAT HAD COME LOOSE. SERVICEABLE VENT FLOAT VALVE, PN 9914268-4, SN 397, REMOVED FROM ACFT, INSTALLED IAW MODEL MM, REV 30, 28-11-03 , REV 23 AND FAILED VALVE ROUTED FOR REPAIR.