What was found
OVERHAULED RH ENGINE WAS INSTALLED ON THE AIRCRAFT. AFTER TEST FLIGHT, AN OIL LEAK WAS NOTED FROM THE #6 CYLINDER BASE. THE CRS THAT OVERHAULED THE ENGINE INSTRUCTED US TO REMOVE THE #6 CYLINDER TO CHECK FOR ISSUES. DURING THE REMOVAL OF THE CYLINDER, IT WAS NOTED THAT ALL OF THE CYLINDER HOLD DOWN NUTS HAD TORQUE-SEAL APPLIED. HOWEVER, THE UPPER AND LOWER FORWARD THROUGH BOLT NUTS WERE ONLY HAND-TIGHT. THE CYLINDER WAS REMOVED WITH NO OTHER ANOMALIES NOTED. AFTER REINSTALLATION OF THE CYLINDER WITH A NEW CYLINDER BASE O-RING AND PROPER TORQUE APPLIED TO ALL HOLD DOWN NUTS, THE CYLINDER NO LONGER LEAKED OIL.