If the oil temperature is too high, it will have a serious impact on the life of the oil. The hazards to the oil and hydraulic system are as follows: (1) The oil is oxidized, the viscosity is increased, and the viscous resistance is increased, which may cause the actuator to be slow and cause the system. (2) Accelerate the consumption of additives in the oil, affect the anti-oxidation, anti-rust and anti-wear properties of the oil, causing the wear of the hydraulic components of the system; (3) After the oil is oxidized, it generates acidic substances and causes corrosion to the hydraulic components. (4) Oxidation produces colloidal substances such as sludge, blocking the damper orifice and the slit valve port, etc., causing the valve member to jam. Therefore, once the hydraulic system is too hot, you need to find out the cause. For hydraulic oils affected by high temperature, they should not be used blindly. Instead, the oil should be thoroughly tested before deciding whether to continue using it according to the test results.