(1) Clean the dust and oil stains on the surface of the driver's cab and the shell; conduct a thorough cleaning once a week;(2) Check whether the clearance of the brake system is appropriate;(3) Check whether the key on the coupling and the connecting anchor bolts are tightened;(4) Check if the electric bell and all safety devices are reliable;(5) Inspect the damage status of brake pads and galvanized steel wire ropes;(6) For second-hand gantry cranes, it is important to check whether the circuit breaker of the control panel is tightly closed and whether the carbon brushes of the motor are damaged.

The viscosity of a used gantry crane is a measure of the frictional resistance between molecular structures when expressing the fluidity of hydraulic oil. When the viscosity is too high, it increases the transport frictional resistance in the pipeline, increases kinetic energy loss throughout the entire working process, increases damage to the server under full load, and leads to rapid temperature changes and high operating temperatures, resulting in "cavitation" at the main pump's suction end. When the viscosity is too low, it cannot ensure good lubrication standards for construction machinery and equipment, increases the damage to components, and increases system leaks, leading to high fuel pump capacity and reduced efficiency. The actual selection depends on the pressure of the hydraulic transmission system, operating temperature, and the movement speed of the components. For high pressure and high temperature applications, low viscosity is recommended, while for high-speed movements, high viscosity is preferred.Excellent viscosity-temperature characteristics. Viscosity-temperature characteristics refer to the level of change in hydraulic oil viscosity with temperature, generally expressed by the viscosity coefficient. The higher the viscosity coefficient, the smaller the decrease in hydraulic oil viscosity with temperature rise during the operation of the hydraulic transmission system, thereby preventing excessive internal leakage in the hydraulic transmission system. The working conditions of construction machinery equipment are generally extreme, and the temperature of gear oil changes with load and operating temperature throughout the entire working process. Therefore, the viscosity coefficient should generally not be less than 90.