What was found
FLIGHT 4550, CREW REPORTED THAT DURING CRUISE, RECEIVED A HYDRAULIC 1 LOW QTY ADVISORY FOLLOWED BY HYDRAULIC SYSTEM 1 FAIL. FOLLOWED AOM PROCEDURES AND HYDRAULIC POWER WAS NOT RECOVERED. DIVERTED AND DECLARED AN EMERGENCY. AIRCRAFT LANDED SAFELY WITHOUT INCIDENT. FLUID WAS POURING OUT OF THE NR 1 ENGINE. SHUT DOWN ENGINE. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED THE NR 1 EDP IAW AMM 29-10-03. OPS AND LEAK CHECKED GOOD. REMOVED AND REPLACED THE HYDRAULIC PRESSURE LINE IAW AMM 29-10-20. OPS AND LEAK CHECKED GOOD. REMOVED AND REPLACED FILTER ELEMENT IAW AMM 29-10-08. OPS AND LEAK CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.