... or bottom, oil cylinder immersed in the oil tank liquid level of the fuel in the tank, a filter head, and a ... replacement, or repair system, only need to unscrew filter end cap ( cleaning cover ), the self-sealing valve is automatically closed, ... open (open value : the vacuum0.02MPa ), in order to avoid the air suction pump has fault. But this should stop to replace or clean the filter, in order to ...