What was found
DURING FUELING FUELER REPORTS FUEL LEAKING INTO CENTER TANK. [07-31-07] ACCOMPLISHED PRESSURIZED FUEL VALVES FOR 15 MIN NO LEAKS FOUND. SUSPECT REFUEL DRAIN BACKFLOW (NORMAL CONDITION). NO HISTORY OF OTHER FUEL LEAKS. 24 HOURS LATER, ACCOMPLISHED FUELING AND DEFUELING OF LT AND RT FUEL TNKS PER 767 FOM. NO FUEL LEAK TO CTR TNK WAS FOUND. UNABLE TO DUPLICATE ON GROUND. A/C COMPLETED SEVERAL WEEKS OPERATION WITH NO FURTHER REPORT OF FUEL LEAKING.