The maintenance of big forklift truck hydraulic system is different from that of other mechanical systems. The maintenance of hydraulic system is relatively simple, but it has a great impact on the performance, efficiency and life of the hydraulic system. The maintenance of forklift hydraulic system can be carried out according to the following steps.

1. First, clean the dust on the surface of the entire hydraulic system structure, and focus on checking whether there is leakage at the joints, electronic components and joints. If the pipe joint is loose, it needs to be re-tightened, but not too tight, because if it is too tight, it will cause its deformation and increase leakage.

2. The oil level in the heavy duty forklift tank should be checked frequently. The liquid level should be between the upper and lower limit positions of the oil dipstick. If the oil is insufficient, it should be filled in time. The following two principles should also be noted for the selection of hydraulic oil: First, hydraulic oil should be selected, and mechanical oil should not be used instead of hydraulic oil; second, avoid mixing two hydraulic oils.

3. Maintenance personnel or forklift drivers need to check the contamination of hydraulic oil frequently. During the inspection, you can insert a glass tube into the bottom of the oil tank to take a sample and drop it on the filter paper. If it is a yellow ring-shaped pattern, it means that the hydraulic oil has been slightly contaminated, but you can temporarily not consider changing the oil; if it is a dark black dot-shaped pattern, it means that the hydraulic oil is severely contaminated, and you should consider replacing the new hydraulic oil immediately or filtering the old hydraulic oil.
4. Before changing the hydraulic oil, the forklift oil tank must be cleaned. The purpose of cleaning is to remove the products of the deterioration of the working oil, rust and foreign matter deposited in the oil tank. When changing the oil, open the screw plug at the bottom of the oil tank and drain the oil. Remove the cleaning cover of the oil tank and wipe the bottom of the oil tank clean, but it should be noted that you cannot use cotton cloth to wipe it, you can choose to use a sponge. Remove the oil filter in the oil tank and soak it in kerosene. If possible, it is best to soak it for about 12 hours.
5. The residual oil in the forklift hydraulic system will contain a lot of dirt. If necessary, you can add oil to flush it. When flushing, you can inject the cleaning oil into the oil tank, but you must pay attention to inject enough, slightly higher than the minimum oil level, so that the hydraulic system can operate safely. Then circulate the cleaning oil in the entire hydraulic system for 15-20 minutes to flush the residual oil in the system's internal organs back to the oil tank, and then completely drain the cleaning oil from the oil tank. In order to ensure the cleanliness of the oil, we must clean the oil filter when changing the oil, and we also need to filter it when refueling. After refueling to the highest oil level line of the oil tank, start the hydraulic pump, input oil into the system, and then add oil to the oil tank. Repeat this process until the oil in the tank remains within the oil level range.