What was found
GVA - APPROXIMATELY 90 MINUTES AFTER TAKEOFF, CREW REPORTED LOSS OF NR 1 ENGINE OIL QUANTITY AND OIL PRESSURE FLUCTUATION OF 30-40 PSIG. ENGINE NR 1 WAS SHUT DOWN AND AIRCRAFT DIVERTED TO LYS AND LANDED WITHOUT FURTHER INCIDENTS. NO EMERGENCY WAS DECLARED. GROUND MAINTENANCE DURING INSPECTION OF NR 1 ENGINE REVEALED A LEAK AT LT ENGINE DRIVEN HYDRAULIC PUMP. FURTHER INSPECTION REVEALED A DEFECTIVE GARLOC SEAL AT LT ENGINE DRIVEN HYDRAULIC PUMP ACCESSORY GEARCASE. THE DAMAGED SEAL WAS REMOVED AND REPLACED WITH A NEW SEAL. A/C WAS RETURNED TO SERVICE FOR FURTHER FLIGHTS. (X)