What is the thin tube next to the oil filler of the loader gearbox?

Raise the horizontal position. The thin tube next to the oil filler of the loader gearbox is used to balance the air pressure inside and outside the gearbox and improve the horizontal position, that is, to enhance the wading ability. This machine is a kind of earthwork construction machinery, which is widely used in highway, railway, building, hydropower, port, mine and other construction projects.