Replace it regularly. A good clutch oil must have good fluidity at low temperatures, good rust resistance, and resistance to rubber expansion. At the same time, the boiling point must be high enough, because the clutch operating temperature is about 200 degrees. It also has antioxidant properties. The symptom of clutch oil shortage is that the clutch pedal is softer than before and the clutch fails to work. In most cases, the clutch plate cannot be completely separated after depressing the clutch pedal.