What was found
ON FLIGHT THE ACFT EXPERIENCED A LARGE FUEL IMBALANCE IN CRUISE FLIGHT DUE TO A RT ENGINE FUEL LEAK. THE ACFT DECLARED AN EMERGENCY AND DIVERTED. WHEN THEY ARRIVED THE RT FUEL QUANTITY WAS 1500 KG LESS THAN THE LT. AN O-RING WAS FOUND LEAKING AT THE RT HP FUEL PUMP FEED LINE. THE O-RING WAS REPLACED AND THE ACFT RETURNED TO SERVICE. THE RT HP FUEL PUMP HAD BEEN REPLACED ON 9 FEB 11 AND LEAK CHECKS CARRIED OUT, NEW O-RINGS WERE USED. THE ACFT HAD FLOWN 6 LEGS SINCE THE PUMP CHANGE, PRIOR TO THE OCCURRENCE FLIGHT. A/C TIMES: TSN 46717, CSN 14812. THE HP FUEL PUMP WAS REPLACED ON 9 FEB 11 AT A/C TIMES: TSN 46696, CSN 14805.