Hydraulic fluid is equivalent to the blood in our body.，It plays the role of energy transmission in hydraulic system.、Anti-wear、System lubrication、Anti-corrosion、Rust-proof、Cooling and the like，If not replaced for a long time, the hydraulic oil will be oxidized and deteriorated.、The anti-wear property is reduced、Viscosity is not up to、Problems such as lack of cleanliness，Causing failures such as stuck valve，Affect the normal use of the equipment。

 Recently, we have received two cases of customer feedback related failures.：

We can see from Figure 1 that，The vehicle is in working condition.，The speed value of No.1 meter is obviously higher than that of the other two channels.。

  

From Figure 2，In the stopped state，Number one gauge has speed.，The actual observation of the rear No.1 gauge is also operational.。

Video one is another customer feedback phenomenon.，The customer had the hydraulic oil replaced a month ago，The hydraulic system was not operated thoroughly for a long time after replacement，The hydraulic oil filter element has not been replaced either，More than 20 days later, during the construction process, the auxiliary engine could not start normally.，Comprehensive inspection test，The problem is the No.3 dispensing system.，Start the auxiliary engine in the stop state，No.3 spreading system auger and gauge have no speed，However, there is an obvious phenomenon of high hydraulic pressure。Shut down the road distribution system，The auxiliary engine can be started normally.。

In this case, we can handle the problem by operating the manual bolts between the valve bodies.。

As shown in video 2，If the stuck valve is not serious，This phenomenon will soon disappear.，If the stuck valve is severe，Causing the auxiliary engine to fail to start normally，It can be operated with others.，The operation method is as follows：1、Single opening of each distribution system or single opening of single auger or meter，Determine the auger or gauge with stuck valve。2、Leave one person in the cab，Turn on the key switch to start the auxiliary engine while another person manually controls the bolts between the proportional valves with tools in the front compartment，If the jam is not too serious，Recover after a few operations，If multiple operations fail to recover，It may be necessary to remove the valve body。If the valve core is worn seriously，It is also possible to replace the single-piece valve body。

The problem of stuck valve is that the hydraulic oil is not replaced for a long time.、Caused by hydraulic oil filter element or failure to pay attention to the cleanliness of the environment when adding hydraulic oil，When such problems occur, we should immediately check the quality of hydraulic oil.、Hydraulic tank filter element、Replace the filter element，That's the only way，We can better ensure the quality of replacement and the operation of the vehicle.。