支六角批就快爛 粒縲絲都未上好 ===> Use the screw to make the hole bigger before actually screwing it on to the car (though not too big, otherwise will be too loose). Get a hex screw driver with a bigger handle from Ap Liu Street.
牙差漏油 ===> Take it apart and re-assemble. Make sure the rubber seal is fitted properly. Make sure the 4 screws are tight.