The hydraulic system is the main factor leading to the aerial work truck lifting platform can not rise, the situation is as follows:
1. Hydraulic circuit does not work. Hydraulic circuit does not refer to the hydraulic pipeline blockage, hydraulic fluid can not reach the hydraulic cylinder. Hydraulic circuit clogging is mainly in the hydraulic system of the various valves (one-way stop valve, directional valves, control valves, etc.), resulting in valve clogging are: hydraulic oil is dirty, the hydraulic oil has solid particles, resulting in the valve stuck or clogged; valves mechanical reasons for the valves can not open the valve clogging; solenoid valves or control valves, electrical part of the reasons for the valves can not be opened.
2. Hydraulic system pressure is too low, resulting in hydraulic lifting platform can not lift. The main reasons for the hydraulic system pressure is too low: the relief valve is damaged or the setting value is too low, especially after overhauling and adjusting the setting value of the relief valve, due to improper adjustment, it is easy to appear that the setting value of the relief valve is small, resulting in low system pressure, and the relief valve is damaged, it will also result in low system pressure; serious leakage of the hydraulic system will also lead to low pressure of the hydraulic system, for example, when there is serious leakage of the hydraulic pipeline, or when there is serious leakage of the cylinder, it will also lead to low hydraulic system pressure, and the aerial work platform with load can not be lifted. It will also lead to low pressure of the hydraulic system, and the aerial lifting platform with load can not rise.