What was found
(CAN) DURING GROUND RUNS AFTER NR 1 ENGINE REPLACEMENT, NR 2 ENGINE WAS FOUND TO HAVE A MAJOR OIL LEAK. 6 LITERS. A LEAK CHECK RUN WAS CARRIED OUT AND OIL WAS LEAKING FROM THE PROPELLER SHAFT OIL SEAL AREA. ON FURTHER INVESTIGATION, THE OIL WAS COMING FROM THE SEAL DRAIN LINE AND THE HYDRAULIC. PUMP GEAR SHAFT OIL SEAL WAS FOUND MIGRATED OUT OF THE SEAL CARRIER. ON ADDITIONAL INVESTIGATION THE ENGINE DRAIN MANIFOLD OVERBOARD DRAIN AND EJECTOR WERE FOUND CLOGGED. THIS MAY HAVE CREATED A BACKPRESSURE CAUSING HYDRAULIC. PUMP GEAR SHAFT SEAL MIGRATION RESULTING IN SUBSEQUENT OIL LOSS THROUGH THE DRAIN LINE AND OUT AT THE PROPELLER SHAFT SEAL AREA.