When severe wear on the excavator hydraulic excavator has a fatal impact, so the excavator such problems must be solved in time. Hydraulic excavators find the cause of the fault repair from the following three points: endoleak (1) Check the boom cylinder easiest way is to repair hydraulic excavator boom is raised, to see whether there is a significant decline in freedom. If you disassemble the fuel tank to check the whereabouts of obvious, such as worn seals should be replaced. (2) Check the control valve first cleaning valve, check valve wear, such as wear and tear should be replaced. If there is still no change after the valve is installed, and then check the control valve spool wear, the gap is generally limits the use of 0.06MM, badly worn should be replaced. (3) to measure the pressure of the pump if the pressure is low, then make adjustments, plus the pressure is still not tune up, then pump heavy wear. First, the general cause of the boom with a load that can not ascend the main reasons are: 1, hydraulic excavator heavy wear serious leak at low speed pump; high-speed operation, the pump pressure is slightly increased, but due to wear and internal leakage of the pump , volumetric efficiency decreased significantly, it is difficult to reach the rated pressure. Exacerbated by long working pump wear, temperature rise, resulting hydraulic components and seals of aging and wear, damage, loss of sealing ability, hydraulic oil deterioration, leading to failure. 2, hydraulic boom cylinder component selection unreasonable non-standard specifications for the 70/40 series, the seal is also non-standard parts, high manufacturing cost and inconvenience of replacing the seals. Boom cylinder bore small, is bound to make the system set pressure is high. 3, the hydraulic control valve system design unreasonable and hydraulic steering pump for a single series, the safety valve set pressure points 16MPA, and rated working pressure of the hydraulic pump for 16MPA. Pump often work at full load or prolonged overload (high pressure) situation, and the system has a hydraulic shocks, oil changes for long periods, hydraulic oil contamination, increased pump wear, so that hydraulic pump shell burst (after have been found such failure). Second, improve and effect (1) improve the hydraulic system design has been repeatedly demonstrated, excavator hydraulic pump repair last priority valve and the use of advanced load-sensing hydraulic steering gear form. New system in accordance with steering requirements, assign priority traffic, regardless of the load size, the steering wheel speed can ensure adequate oil level, the remaining portion of the circuit may all be used to supply the working device, thereby eliminating the excessive fuel supply caused by the steering circuit power losses, improve system efficiency and reduce the hydraulic pressure of work. Reduce hydraulic excavator heavy wear. (2) optimize the design of the boom cylinders and hydraulic modeling to reduce system operating pressure. By optimizing the computing boom cylinder with standard series 80/4. Displacement hydraulic pump by 10ML / R increased to 14ML / R, the system set pressure for 14MPA, meet the boom cylinder lifting force and speed requirements. (3) strengthen the routine inspection and maintenance should also be noted in the course of the proper use and maintenance of the excavator, regularly add or replace hydraulic oil, hydraulic oil to maintain cleanliness, strengthen the routine inspection and maintenance. Avoid heavy wear hydraulic excavators, hydraulic excavators in order to reduce maintenance times.