What was found
(CAN) OIL LEAKAGE OCCURRED ON 2 SEPARATE OCCASIONS ON PROPELLER. OIL FOUND LEAKING FROM CYL PLUG AND START LATCH HOLES. UPON DISSEMBLY OF THE PROP DOME FOUND PISTON O-RING TO BE DAMAGED, EXHIBITING SIGNIFICANT TWISTING AND DETERIORATION. THE PROPELLER HAD JUST UNDER GONE PRESSURE TESTING AT A PROPELLER OVERHAUL FACILITY WITH NO REJECTABLE INDICATIONS. A SECOND PROPELLER WAS INSPECTED AND FOUND TO HAVE THE SAME PROBLEM.