What was found
DFW - FLT 544 - DURING FINAL APPROACH, THE NR 1 HYDRAULIC SYSTEM LOW LIGHT ILLUMINATED ON THE MULTIFUNCTION DISPLAY UNIT (MFDU). CREW ACCOMPLISHED CHECKLIST FOR HYDRAULIC SYSTEM LOW QUANTITY AND ALTERNATE FLAP EXTENSION AND GEAR EXTENSION WAS USED. AIRCRAFT LANDED DFW WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND NR 1 ENGINE HYDRAULIC PUMP PRESSURE LINE FITTING LEAKING. REPLACED NR 1 ENGINE DRIVEN HYDRAULIC PUMP PRESSURE LINE FITTING O-RING AND SERVICED HYDRAULIC SYSTEM. SYSTEM WAS CHECKED UNDER PRESSURE WITH NO FURTHER LEAKS NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)