What was found
FUEL QUANTITY DISAGREE #1 TANK WENT 1000LBS LOW ; FUEL QUANTITY DISAGREE #1 TANK WENT 1000 LBS OUT OF BALANCE QUICKLY. FUEL FLOW NORMAL. QUANTITY WORSE AT ALTITUDE; AND IN BALANCE ON THE GROUND / REMOVED PANELS NOTED ABOVE PER AMM 28-11-11-000-801-NG (MAIN TANK ACCESS DOOR REMOVAL - PERMANENT); C/W STEPS 5;6;7 AND 8.; REMOVED AND REPLACED FUEL TANK UNITS #1; COMPENSTOR; #5; #8 AND #9. PERFORMED GOOD LEAK CHECK OF FUEL PANELS AND OPS CHECK OF FQIS REF AMM 28-41-21; 28-11-11 AND 28-41-00