What was found
LACK OF LUBRICATION CAUSED BOLT TO SEIZE IN FLAP DRIVE PULLEY RIGHT BUSHING. OVER PERIOD OF TIME, WITH EVERY CYCLE OF FLAPS THIS BOLT ROTATING ELONGATED TOP AND LOWER BRACKETS . ON PREFLIGHT PILOT NOTED SOMETHING STREAKING FROM LOWER SKIN. REPLACEMENT OF BRACKETS, BOLT, BUSHING WERE NECESSARY.