A GJW111 excavator in the course of the work appeared slow movement of the whole machine, weak work failure phenomenon. Fault reasons are: hydraulic pump wear, servo regulatory agencies stagnation, to the system to provide insufficient hydraulic flow, the main safety valve failure, the engine output power shortage, the pilot system, such as lack of pressure. In the process of troubleshooting, no-load or work, the engine speed is normal, no black smoke phenomenon; the main system of pressure and flow within the calibration range. Analysis of fault focus on the main safety valve and hydraulic pump. In the principle of easy first, the main safety valve first adjusted, no significant improvement; followed by decomposition, cleaning the main safety valve and found no significant parts of the main safety valve wear and tear, springs without breaking, reassembly and adjustment of the fault remains; finally replaced A new main safety valve, but without any improvement, the system pressure is still between 18-24Mpa (calibration pressure of 30Mpa); check the hydraulic oil and filter are normal, and that the hydraulic pump less likely to malfunction. Repair staff in the test machine test process, the brake handle is not intended to stop on the brake position, the phenomenon of failure completely disappear. According to the principle of stop brake valve analysis, the main fault is to stop the brake valve adjustment is not in place. When the brake is released, the valve stem of the stopping brake valve is not in place to cause a part of the pilot oil to flow into the stopping brake cylinder, and part of the brake valve flows back to the fuel tank through the stop valve, resulting in insufficient pressure in the pilot system. This in turn causes the valve stem to be dispensed with in place of the operating valve, which acts as a choke or leak to the main system flow. As a result, the entire machine is weak and the power is slow. Dismantle the stop brake valve and found that the adjusting bolt of the putter is loose, the length of the putter is shortened, and the phenomenon of the failure completely disappears after adjustment. This article keyword search: valve supply information