Usually, the hydraulic oil of the excavator should be replaced regularly, otherwise, it will deteriorate and the sediment produced will not be cleaned for a long time, resulting in the lack of power in the hydraulic system, which will lead to the inability of excavation. Generally, the hydraulic oil should be replaced once a month or so.

　　我们先要准备好更换液压油的工具，然后开始一步步的进行更换。用扳手和螺丝刀，把各个管接头拆卸掉，把旧的液压油全部排放干净，用事先准备好的装废油的桶接油，液压油有很强的污染性，不能随意排放，要统一进行回收处理。旧的液压油排放干净之后，用抹布把油箱底部的沉淀杂质清理干净，液压系统滤芯如果清理不干净的话，直接更换新的，然后加注同型号的液压油。

　　We need to prepare the tools to change the hydraulic oil, and then start to change step by step. First, use a wrench and a screwdriver to remove all the pipe joints, drain all the old hydraulic oil, and use a prepared bucket to collect the waste oil. The hydraulic oil is highly polluting and cannot be discharged at will. It should be recycled in a unified way. After the old hydraulic oil is drained, clean the precipitated impurities at the bottom of the oil tank with a rag. If the filter element of the hydraulic system cannot be cleaned, replace it with a new one directly, and then fill the same type of hydraulic oil.

　　如果是给小型挖掘机更换不同型号的液压油，千万不可把不同型号的混合使用，这样会加速变质的时间，应该在旧油排放干净之后，加入少量新的型号的液压油，然后让液压系统运转一会，这样做的目的是把旧油冲洗掉，然后把混合油排放干净之后，再加注新型号的液压油。

　　If it is to replace different models of hydraulic oil for small excavators, do not mix different models, which will accelerate the deterioration time. After the old oil is drained, add a small amount of new models of hydraulic oil, and then let the hydraulic system run for a while, so as to wash out the old oil, and then drain the mixed oil, and then add the new model Hydraulic oil.