What was found
DFW - FLT 1178 - DURING CRUISE WHILE EN ROUTE MEX-DFW, LOST 'A' HYDRAULIC SYSTEM QUANTITY AND PRESSURE ACCOMPLISHED MANUAL GEAR EXTENSION AND LANDED DFW WITHOUT INCIDENT. LANDING WAS NOT OVERWEIGHT. REPLACED HYDRAULIC 'A' SYSTEM PRESSURE LINE AT 'A' SYSTEM HYDRAULIC MODULE AND 'A' SYSTEM FILTERS. ACCOMPLISHED LEAK CHECK AND GEAR SWING. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)