What was found
(CAN) TWO HOURS INTO FLIGHT, LOST ALL BLUE SYSTEM HYDRAULIC FLUID, APPROXIMATELY 45 MINUTES LATER, THE BLUE SYSTEM HYDRAULIC RESERVOIR OVERHEAT LIGHT CAME ON AND REMAINED ON FOR DURATION OF THE FLIGHT. MAINTENANCE FOUND BLUE SYSTEM ENGINE HYDRAULIC PUMP CASING LEAKING. PUMP REPLACED AND SYSTEM CHECKED SERVICEABLE.