We have summed up the main causes of the loader's failure in work. Today we will explain them to you

　　1. The system pressure is too low

　　Connect a pressure gauge with a range of 25MPa at the pressure point of the distribution valve, so that when the engine and hydraulic oil are at the normal working temperature and the engine speed is about 1800r / min, operate the distribution valve rotary bucket slide valve to make the bucket tilt back to the bottom, and the pressure displayed on the pressure gauge shall be 17Mpa. If it is lower than this value, the safety valve shall be disassembled and inspected to check whether the pilot valve spring is broken, whether the seal is good, whether the main valve core is stuck and whether the damping hole is blocked, etc. If there is no problem above, adjust the pressure regulating screw to make the system pressure reach the normal value.

　　2. Inner leakage of boom cylinder or bucket cylinder

　　Put the piston of boom cylinder or rotating bucket cylinder to the end respectively, remove the oil pipe without rod cavity, and make the rod cavity of boom cylinder or rotating bucket cylinder continue to be filled with oil. If there is a lot of oil leaking out from the oil port of the rodless chamber (the normal leakage should be ≤ 30ml / min), it means that the piston sealing ring is damaged and should be replaced; it can also make the bucket full of load, lift to the limit position, place the boom control lever in the middle position, and turn off the engine, observe the sinking speed of the boom (it should be & lt; 40mm / h normally); then, place the boom control lever in the rising position, if At this time, the boom sinking speed is obviously accelerated, which means that the internal leakage occurs in the hydraulic cylinder; if the sinking speed does not change significantly, the internal leakage is caused by the distribution valve.

　　3. Internal leakage of distribution valve

　　The main causes of internal leakage of the distribution valve are: the main valve core of the general safety valve is stuck; the fit clearance between the valve rod and the valve body is too large (the normal fit clearance is 0.025 ~ 0.040mm); the valve rod or valve body is pulled; the seal is damaged, etc.

　　4. Internal leakage of working gear pump

　　The internal leakage of gear pump is shown as follows: the noise is high during operation, the higher the engine speed, the greater the noise; a large number of copper chips can be seen in the oil filter. The gear pump shall be disassembled and inspected, and the end clearance (normal value is 0.100-0.140mm) of the gear, the meshing clearance (normal value is 0.005-0.015mm), the radial clearance (normal value is 0.100-0.200mm), and the seal shall be inspected. If it is out of tolerance or damaged, it shall be repaired or replaced.