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、若小型混凝土攪拌車液壓泵有油液輸出，查看溢流閥工作是否正常。若不正常，則可能是壓力油路中的某個閥有污物或其他原因卡住，處于回油位置，致使壓力油路與溢流回路短路，也可能是管接頭松脫，或處于壓力油路中的某些閥泄漏嚴重，或液壓缸、液壓馬達的密封損壞，嚴重泄漏。排除方法是拆開有關(guān)閥進行清洗，檢查密封間隙的大小及各種密封裝置，密封裝置損壞應(yīng)更換。

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、若水泥小型混凝土攪拌車的液壓泵輸出流量隨壓力升高而顯著減小，且壓力達不到規(guī)定值，則是由于液壓泵磨損后間隙增大所致。排除方法是測定液壓泵的容積效率，即可確定該泵是否能繼續(xù)使用，對磨損嚴重的零件，應(yīng)進行修配或更換。

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、小型混凝土攪拌車的液壓系統(tǒng)能建立正常壓力，而某些管路或液壓缸中無壓力，可能是由于管路、小孔或節(jié)流閥、換向閥等部位堵塞。此時應(yīng)逐段檢查壓力和有無油液通過，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.