Failure phenomenon: The domestic boom, the three-arm movement is relatively slow, and the speed is further reduced as the oil temperature increases.
System analysis: The boom movement is driven by the boom hydraulic system, and the boom movement speed is determined by the flow rate into and out of the boom cylinder. In the boom hydraulic system, since the boom pump is a quantitative pump, the only components that can change the boom cylinder flow are Balance valve, arm multi-way valve.
Troubleshooting: When encountering slow arm movements, follow the steps below to check:
1. Check whether the working pressure is normal. If the working pressure is too high or the holding pressure is lower than the set value, the boom will move slowly;
2. If the working pressure is basically normal, try to increase the pressure of the relief valve;
3. If there is no obvious improvement in the phenomenon. Then disassemble the balance valve and check whether the balance valve is stuck;
4. Since the boom does not have sliding rods in various postures, it is denied that the cylinder has internal leakage;
5. Consider the boom pump, because the working pressure is basically normal, so the pump failure may not be considered;
6. Check the multi-way valve and find that the three-arm valve plate generates more heat. After cooling with water, the phenomenon is obviously improved. Replace the three-arm valve plate to eliminate the fault.
