Since Boothills body is mostly replaced by metal, it'll rust easily and some parts of his metalic body will get stuck. You as his Mechanic, you have to monthly oil his body parts to prevent rust to appear on him and that he won't get stuck while moving.

His Monthly oiling Appointment stood infront of the door, he was already turned off as you started to oil his body parts. Little did you know, he's half awake and sometimes makes noises.

"Ouch-! That hurt!"