What was found
DURING FLIGHT CREW NOTICED THERE WAS A LARGE DISCREPANCY BETWEEN INDICATED FUEL QUANTITY AND AMOUNT OF FUEL USED AS SHOWN ON FLIGHT MANAGEMENT SYSTEM. UPON LANDING CREW NOTICED FUEL DRIPPING FROM SEVERAL AREAS ON THE UNDERSIDE OF THE AIRCRAFT. FUEL WAS FOUND IN THE AFT BAGGAGE COMPARTMENT. WHILE TROUBLESHOOTING THIS PROBLEM, MAINTENANCE PERSONNEL DISCOVERED THAT WHEN THE LT FUEL BOOST PUMP WAS OPERATED IT WAS CONTINUOUSLY PUMPING FUEL OUT OF THE PUMP HOUSING OVERBOARD DRAIN. THE INTERNAL SEALS IN THIS PUMP HAD FAILED CAUSING THIS PROBLEM. DEFECTIVE PUMP WAS REPLACED WITH AN OVERHAULED UNIT AND AIRCRAFT WAS OPERATED WITH NO FURTHER PROBLEMS.