1. Check whether the hydraulic pump of small concrete mixer can output hydraulic oil. If it is a new hydraulic pump and there is no hydraulic oil output, it may be that the pump body has casting defects (shrinkage cavity, sand hole, etc.), so that the oil suction cavity is connected with the oil pressure cavity and the oil pressure capacity is lost. It should be replaced by the manufacturer in time. If it is not a new hydraulic pump and there is no hydraulic oil output, it may be that the steering of the pump is not right and the parts are seriously worn or damaged, so it should be replaced in time.
2、若小型混凝土搅拌车液压泵有油液输出，查看溢流阀工作是否正常。若不正常，则可能是压力油路中的某个阀有污物或其他原因卡住，处于回油位置，致使压力油路与溢流回路短路，也可能是管接头松脱，或处于压力油路中的某些阀泄漏严重，或液压缸、液压马达的密封损坏，严重泄漏。排除方法是拆开有关阀进行清洗，检查密封间隙的大小及各种密封装置，密封装置损坏应更换。
2. If the hydraulic pump of small concrete mixer has oil output, check whether the relief valve works normally. If it is abnormal, it may be that one of the valves in the pressure oil circuit is stuck in the oil return position due to dirt or other reasons, resulting in a short circuit between the pressure oil circuit and the overflow circuit. It may also be that the pipe joint is loose, or some valves in the pressure oil circuit are seriously leaking, or the seals of the hydraulic cylinder and hydraulic Mada are damaged, resulting in serious leakage. The elimination method is to disassemble the relevant valve for cleaning, check the size of the sealing gap and various sealing devices, and replace the damaged sealing device.
3、若水泥小型混凝土搅拌车的液压泵输出流量随压力升高而显着减小，且压力达不到规定值，则是由于液压泵磨损后间隙增大所致。排除方法是测定液压泵的容积效率，即可确定该泵是否能继续使用，对磨损严重的零件，应进行修配或更换。
3. If the output flow of the hydraulic pump of the small cement concrete mixer decreases significantly with the increase of pressure, and the pressure does not reach the specified value, it is due to the increase of the gap after the wear of the hydraulic pump. The elimination method is to measure the volumetric efficiency of the hydraulic pump, which can determine whether the pump can continue to be used. The parts with serious wear should be repaired or replaced.
4、小型混凝土搅拌车的液压系统能建立正常压力，而某些管路或液压缸中无压力，可能是由于管路、小孔或节流阀、换向阀等部位堵塞。此时应逐段检查压力和有无油液通过，找出原因，加以排除。
4. The hydraulic system of small concrete mixer can establish normal pressure, but there is no pressure in some pipelines or hydraulic cylinders, which may be due to the blockage of pipelines, small holes or throttle valves, directional valves and other parts. At this time, it is necessary to check the pressure section by section and whether there is oil passing through, find out the cause and eliminate it.
