What was found
(CAN) NR 2 ENGINE HAD OIL PRESSURE FLUCTUATION IN CRUISE. ON ROLL-OUT, THE NR 2 ENGINE OIL PRESSURE DROPPED AND THE LOW OIL WARNING ILLUMINATED. THE ENGINE WAS SHUT DOWN. POST-FLIGHT INSPECTION FOUND OIL ON THE ENGINE NACELLE AND THE GEAR LEG. FURTHER INSPECTION FOUND THE OIL QUANTITY 5 QUARTS LOW. THE OIL HAD LEAKED FROM THE HYDRAULIC PUMP SEAL DUE TO A PRESSURIZED GEARCASE RESULTING FROM A LEAKING COMPRESSOR SEAL. THE HYDRAULIC PUMP SEAL AND THE COMPRESSOR SEAL WERE REPLACED AND THE AIRCRAFT RETURNED TO SERVICE.