Find out the source of the fault. There are two points to pay attention to, one is the hydraulic pump; The metal scraps of the hydraulic pump can be found in the magnetic oil drain plug under the oil pump. If any, it indicates that the pump has been worn and should be disassembled and repaired if necessary. Second, hydraulic cylinder; The inner wall of the cylinder barrel and the head of the piston rod are often subjected to sudden change of impact pressure, which is easy to cause problems when the engine is repaired at high temperature. The fault of this machine is caused by the metal chips peeled off from the inner wall of the bucket cylinder being pulled and stuck in the valve a. In short, if there are metal chips or sundries in the hydraulic system, the root cause must be found.
In general, due to the extremely precise cooperation between the valve core and the valve hole of the rotary main control valve and the oil lubrication, it is not easy to generate wear and sundries are difficult to get stuck in it. Therefore, do not disassemble the valve core before the fault point is determined. Because there is oil film in the valve core and the valve hole, the valve core is not easy to pull out. At this time, it is often mistaken that it is stuck by sundries, so the forced method is adopted, which is easy to damage the surface of the valve core; In addition, since most of the repairs are carried out on the construction site, it is difficult to ensure the cleanness of the surrounding environment of the valve during reassembly, so it is easy to get sundries stuck in it.
