Filtering oil is a piece of cake. First take off the top plate of the left boiler, then pick up the heating coil, then open the lower oil drain valve 1 and break it to the right with something long, then turn on the power supply, and the oil drain valve on the right will open, and the metal plate of 1 will break across, so that the jeep will not be full when discharging oil. Then wipe the boiler clean with an L brush and close the oil drain valve.