Air compressor oil, used to check whether the air compressor oil is enough, observe whether the oil is bad to be replaced (the original should be close to the transparent light yellow color, use for a long time will become dark brown or black), at this time to add or change oil air compressor machine commonly 2 ~ 3 months to replace a motor oil (depends on the use of the length of time). The oil level of the air compressor is looked at when it stops. 2/3 of the line above and below the mark should be appropriate. More or less not so good. This is the general standard. A red point is generally marked in the middle of the oil mirror, and the oil level can exceed this point when the air compressor is in the horizontal position. The air compressor has an oil ruler, and the oil level can be between the upper and lower marks after being pulled out at rest. Generally, when the air compressor is loaded (commonly known as pumping), the oil in the oil barrel will enter the compressor, oil lattice, oil and gas separator, cooler and other parts with the increase of temperature, so the oil level will fall below the mirror surface, and part of the oil will return to the oil barrel when unloading, and the oil level will rise at this time. This is normal, as long as the compressor at rest oil level is in the correct position of the oil level mirror can be.