Manufacturer: LESU. The maximum working pressure of the oil pump is 25kg/cm2, the rated working pressure is about 20kg/cm2, and the flow is 100ml/min. This hydraulic system can lift about 20kg! 7, The oil cylinder made of brass makes the hydraulic system more airtight, 4 pieces cylinders enable the dumper to complete two actions: self-unloading and full unloading.