What was found
NR 1 HYDRAULIC SYSTEM LOST ALL PRESSURE AND FLUID AT 26,000 FEET. RETURNED TO RDU. REMOVED AND REPLACED ALL NR 1 SYSTEM HYDRAULIC FILTERS IAW CRJ AMM 29-11-09, 29-11-40, AND 29-11-46. REMOVED AND REPLACED NR 1 SYSTEM ENGINE DRIVEN HYDRAULIC PUMP IAW CRJ AMM 29-11-01. REMOVED AND REPLACED NR 1 ENGINE DRIVEN PUMP PRESSURE LINE IAW CRJ AMM 29-11-52. REPAIRED NR 1 SYSTEM RETURN LINE IAW CRJ AMM 20-22-00. PERFORMED OPS AND LEAK TEST OF NR 1 HYDRAULIC SYSTEM IAW CRJ AMM 29-10-00. ALL OPS AND LEAK CHECK GOOD.