1) The solenoid valve cannot be closed Check whether the seal is damaged, whether the spring is deformed, and check whether the spring assembly is good. When the balance hole of the orifice is blocked, it should be cleaned in time; if there are impurities entering the solenoid valve, the main spool of the solenoid valve and the spool valve sleeve will be stuck due to the small gap, so it should be cleaned. Whether the solenoid valve corresponds to the temperature and viscosity of the oil during operation, if the temperature and viscosity of the hydraulic oil are too high, the corresponding solenoid valve needs to be replaced.
2) The solenoid valve does not work when energized
First of all, check whether the power cord is loose or the wire ends are falling off, and whether the voltage fluctuation is within the specified range; check whether the coil is de-soldered or short-circuited; whether the solenoid coil is burned out, you can remove the wiring of the solenoid valve and measure with a multimeter. The solenoid valve coil is burned out.
3) Internal leakage failure
When internal leakage occurs, it is necessary to check whether the seal is damaged in time; if there is noise when the power is turned on, it should be that the fasteners on the ends have been loose, and they can be tightened.
4) The working pressure of the solenoid valve shall not exceed the rated pressure
When working, pay attention to the pressure gauges before and after the solenoid valve, and it is required that the working pressure should not exceed the rated pressure. When the working pressure exceeds the rated pressure, the solenoid valve should be stopped, and the front and rear manual valves should be closed to prevent the solenoid valve from exploding and leaking.
5) Small excavator solenoid valve maintenance
The driving of the solenoid valve of the excavator is powered by the solenoid coil, which is easily damaged by the voltage shock. Usually, the solenoid valve core is not easy to be damaged, and the solenoid coil burns out more. There are many reasons for the damage of the excavator solenoid valve: long use time, aging and damage of the coil; unstable voltage causing the coil to burn out; the coil circuit is grounded and so on. Solenoid valve coils are usually divided into two types: 12V and 24V. When choosing coils, you must analyze them clearly. Once you make a mistake, the valve core cannot be opened, and the voltage is too large to burn out.
Excavator solenoid coils are the same as many industrial hydraulic solenoid coils and can be used instead. When purchasing, first measure the inner diameter and height with an oil caliper. The inner hole is divided into inch and national standard. It must be measured accurately, and the shape can be ignored (see Figure 4). You need to install the vehicle wire (copper wire) by yourself, and the general wire diameter is 0.85mm and 1.25mm. When installing the wire, pay attention that the positive and negative poles cannot be reversed. Generally, the positive pole is the one with resistance. First unscrew the wiring socket, connect the cut wire and tighten it. If it is loose, it will cause poor contact.
