The Influence of Air on Custom Hydraulic Systems The influence of air on custom hydraulic systems and the protection measures Under normal circumstances, the proportion of air in hydraulic oil is 6-8%. Due to the decrease in pressure, air can escape from the hydraulic oil. At the same time, the bursting of air bubbles causes cavitation in hydraulic components and generates noise. If this situation occurs frequently and severely, it will make the hydraulic system work unstable, thereby reducing the efficiency of the operation.