10591 10591D Locking Fuel Gas Cap for Ford 1987-1996 F-250,Truck Fuel Tank Cap Replaces for 9MGC791 MGC791 31778D Replacement Caps Update by Koerlam, not OE, but quality good as oe

How to use the locking fuel cap?

Step 1 :Put the cap on the fuel tank port and rotate it clockwise

Step 2 :Keep rotating the cap clockwise until it makes clickety-clack sound

Step 3 :Insert the key into the keyhole and turn it to the unlocked status, then rotate the cap anti-clockwise

Step 4 :Keep rotating until the cap can be removed