What was found
(CAN) CREW REPORTED THAT AFTER TAKE-OFF THEY SELECTED GEAR UP AT 125 KNOTS, FLAPS AT 5 DEGREES, AND THE LH SIDE FAILED TO RETRACT, THEY RECIEVED A LH GEAR UNSAFE LIGHT, AS WELL AS A RED UNSAFE LIGHT IN THE HANDLE, THEY COULD HEAR THE HYDRAULIC PUMP STILL RUNNING TO TRY AND RETRACT THE GEAR, THEY SELECTED THE GEAR TO THE DOWN POSITION, AND ATTEMPTED A SECOND RETRACTION SUCCESSFULLY, THE GEAR CAME DOWN AND OPERATED NORMALLY ON APPROACH. MAINTENANCE FOUND LH MAIN LANDING GEAR DOOR ACTUATOR AT FAULT AND LEAKING PAST THE PISTON. REPLACED ACTUATOR WITH A SERVICEABLE UNIT. LEAK AND F/T GEAR SERVICEABLE. GEAR SWING COMPLETED.