What was found
FUEL MIGRATION FL 350. TOP OF DESCENT 0.0. START DESCENT 300. IN DESCENT 600. ON LANDING 1600. AT PARKING 1400. NOTE! LEFT TANK TO CENTER. REMOVED AND REPLACED BOTH CENTER TANK REFUELING VALVES (VALVE, ASSY, FUEL CONTROL), 2 EACH DRAIN CHECK VALVES (VALVE PRESSURE FUEL DRAIN), AND LEFT DEFUEL VALVE (VALVE FUEL SHUTOFF) IAW AMM 28-21-02, 28-21-05, AND 28-26-01. OPS CHECK DUE LEAK CHECK ACCOMPLISHED ON REFUELING VALVES, NO LEAKS NOTED IAW AMM 28-21-02