What was found
FOUND UNWANTED FUEL XFER FROM LT TO CENTER TANK AT A RATE OF 100 LBS IN 3 MINUTES WITH LT FUEL LEVEL INDICATING 30,000 LBS. FOUND FUEL ENTERING CENTER TANK THRU FILL MANIFOLD DRAIN VALVE. SUSPECT O/B FILL VALVE ACCOUNT OF XFER CEASES WHEN LEVEL IS DROPPED TO 10,000 LBS. CONDITION WAS BOOST PUMPS OFF, DEFUEL VALVES CLOSED, FILL VALVES CLOSED, AND XFEED CLOSED. *S/D* TRANSFER WAS FOUND TO BE RESULT OF LEAKS FROM MAIN TANKS TO CENTER TANK AT LEFT AND RIGHT RIB 3 AND THE LEFT OUTBOARD FILL VALVE WAS FAILING TO FULLY CLOSE. THE LEAKS WERE SEALED AND THE FILL VALVE (PN40884-4) REPLACED. THERE HAS BEEN NO FURTHER FUEL TRANSFER.