If it is confirmed through troubleshooting that the bucket overturning is normal due to the hydraulic system fault and only the boom lifting is slow and weak. This shows that the working pump and the main safety valve are working normally. It also shows that the oil quantity and quality of the pipeline and oil filter at the oil inlet end of the pump as well as the oil tank are all right. At this time, it is only necessary to check the boom spool valve, boom oil cylinder, boom oil pipe and its seals. Check whether the oil circuit is blocked. Carry out routine treatment first. Remove the oil pipe, boom spool valve body, valve rod and relevant parts for cleaning. Clean the oil passage and blow it dry with compressed air.
