Analysis of common faults when using excavator long stick

The excavator long stick is very common nowadays, because it can better help the excavator to achieve earthwork excavation operations such as building foundations, river channels, deep trenches, etc., and the performance presented is self-evident, but when using the excavator long stick There will be some failures, what are they?

The excavator walks right and the bucket does not move, and the boom and stick move slowly

Many people reported that this failure occurred after replacing the seal of the control valve assembly. After the test, the pressure of the pump when the bucket is retracted is 1.5Mpa, which is much lower than the normal value of 28.5Mpa. When preparing to exchange the two-way safety valve, it was found that the safety valve on the faulty side was a plug, but a safety valve was installed at the position of the original plug. The machine is normal after exchanging the correct position. It turned out that after the maintenance personnel replaced the seal of the control valve assembly, the safety valve and the plug of the group of valves were installed in reverse.

After being converted into an excavator with an excavator long stick, the whole vehicle is slow and powerless

Some people reported that the oil seal of the pilot pump was just replaced, but it worked normally for ten minutes after the replacement, and then suddenly it stopped working. Based on this situation, it is first suspected that the pilot pressure is insufficient.

After testing the pilot pressure was extremely low, it was decided to disassemble the pilot pump.

The first discovery is that the skeleton oil seal of the input shaft of the pilot pump has been extruded. There are two reasons for this: one is the installation problem, and the other is that the pressure there is too high. Continue to disassemble and find that the direction of the oil seal of the pilot pump is reversed. This is the real cause of the failure. When it first started to work, the skeleton oil seal was not completely damaged and could still work normally. Because the skeleton oil seal can only withstand low pressure, the oil seal was quickly damaged, causing the pilot pressure oil to leak from the damaged part.

The piston rod of the stick cylinder is automatically retracted after the engine is started

After inspection, one of the other actions is normal; two, the stick sinks faster after the boom is lifted. After exchanging the stick pilot pipe, the fault remains the same, indicating that the fault lies in the control valve or stick cylinder, in line with the principle of first easy and then difficult. Disassemble and inspect the control valve stem and find that the valve stem is stuck in the retracted position of the piston rod. After vibrating with a rubber beetle head and a copper rod, take out the valve stem. It can be seen that there are shiny iron ends, and the contact stick sinks faster. It is judged that the root cause of the failure is the strain of the excavator long stick stick cylinder, which is confirmed after dismantling and checking the stick cylinder.

The above is the detailed introduction of Huitong about some common faults that may appear after the excavator long stick is modified, but please don't panic, it can be effectively solved by the correct method.