What was found
FLT 4496 - DURING CLIMB-OUT FROM DFW-CHS, AT APPROXIMATELY 22,000 FEET THE CREW RECEIVED A NR 2 HYDRAULIC LOW PRESSURE WARNING MESSAGE WITH THE SYNOPTIC PAGE SHOWING NO HYDRAULIC FLUID IN THE RESERVOIR. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO DFW, LANDING SAFELY. MAINTENANCE REMOVED AND REPLACED THE NR 2 ENGINE DRIVEN PUMP PRESSURE LINE. OPERATIONAL AND LEAK CHECKS GOOD. AIRCRAFT OK FOR SERVICE. (M)