What was found
AIR TURNBACK, LOSS OF SYSTEM-A HYDRAULICS. SHORTLY AFTER TAKEOFF, NR 2 A-HYDRAULIC LOW PRESSURE LIGHT FOLLOWED BY A-SYSTEM QUANTITY TO ZERO. REMOVED AND REPLACED NR 3 BRAKE FLEX LINE AND A-SYSTEM HYDRAULIC CASE DRAIN FILTER, NO DEBRIS. REPLENISHED A-SYSTEM HYDRAULIC FLUID. RAN ENGINES AND SYSTEMS, LEAK CHECK ON LINES AND FILTERS GOOD.