What was found
(CAN) WHILE IN CRUISE, CREW REPORTED A STEADY DECLINE IN HYDRAULIC FLUID QUANTITY. IN CONJUNCTION WITH DISPATCH, MOC, FLIGHT CREW IT WAS DECIDED THAT A DIVERSION WOULD BE PRUDENT. CREW DECLARED A PAN PAN WITH ATC. LANDING WAS UNEVENTFUL. HYDRAULIC QUANTITY WAS AT 2 PERCENT ON LANDING. OPENED COWLS SUGGESTED HEAVY LOSS OF FLUID. IT WAS NOT DETERMINED IF A PUMP OR LINE HAD FAILED. CFR WAS AVAILABLE AT LANDING. PAX RESPONSE WAS GOOD. RESOLUTION TS IAW FIM 29-11-00-810-805A. CARRIED OUT AMM 05-50-23-200-801A/600, FOUND NR 1 ENG HYDRAULIC PRESSURE LINE QD LEAKING. REPLACED NR 1 ENGINE EDP, CASE DRAIN LINE AND PRESSURE LINE IAW AMM 29-11-01/400. REPLACED CASE DRAIN AND PRESSURE FILTERS SYSTEM NR 1. ENGINE RUN, LEAK CHECKED. SERVICEABLE.