How do I check a hydraulic solenoid valve in order to see whether it is OK or faulty?

hydraulic solenoid valve

If you are related to hardware and tools, you must know about Hydraulics and solenoid valves in it. If you don’t know, it is a system of Hydraulics used for changing the course, opening, and closing off the fluid flow in the machine with the help of a

solenoid-controlled valve. The solenoid is an electric coil turned around a ferromagnetic core, and the valve is operated with that solenoid. Ports are the different chambers of the valve that helps in various operations. Unfortunately, they can be faulty sometimes and show some unexpected behaviors, so few points help in knowing that the Hydraulic Solenoid valve is Faulty or not! In this article, we have given a brief explanation of the Testing of Hydraulic Solenoid Valve.

Why Valves Need testing?

hydraulic solenoid valve 1
Image Source: Mini Hydraulic Power Packs & Hydraulic Power Units

Solenoid valves are susceptible parts, and a slight impurity can cause damage to it. However, they are crucial to the hydraulic machines as it conducts all the operations by the help of electric signals. The solenoid valves constantly work in open humid, and gas-exposed areas, so there is a high chance that they can get corroded and layers of different minerals get stuck on the surface, causing leakages. There are many cases where hydraulic systems have exploded or ruptured due to the cheap and low maintenance of the solenoid valves. So it is crucial to maintain and test the Solenoid valves for any leaks and faults.  

How frequently should the solenoid coil be tested?

The Hydraulic solenoid valves are used under much pressure and have high wear and tear in shorter times due to high load and pressure. Therefore, it should be tested and maintained according to the stress and load are given on it. Usually, it should be tested every two months to three years based on the application.  

What is a Spool in Hydraulic Solenoid Valve?

In a Hydraulic solenoid valve, a spool is a coil packed in a sealed cylindrical case. They have solenoids on two sides, making it a valve that helps in the operation of hydraulic machines. It has inlets for current and electric signals, which transmit itself to the valve and makes the Hydraulics operational.

Here are some ways of checking the solenoid valve to see if it is faulty or not.

Solenoid Valve sealing

The leaking of the valve directly relies upon the tightness of the sealing of the solenoid valve. If there is no ventilation and the valve is in casual use, there will be no air or fluid leakage. However, during a routine operation, if there is a sound of exhaust in the valve, there must be a leakage of air in the solenoid valve. More considerable leakages can be easily found by this method, but it is insufficient for more minor leakages; you need a different trick to find out small air leakage. You need to apply a layer of soapy water on the solenoid valve and check for an air bubble on it, the area which shows bubbles that area is affected and has air leakage. It would be best if you kept an eye on the soapy water amount you are pouring; it shouldn’t go inside the solenoid valve.

hydraulic solenoid valve 3

Image Source: Surplus Center

Switch opening and Closing Speed 

Sometimes the transmission speed of the electric signal is average, and the solenoid valve operation is slow, and the electric signal speed is not followed. This is caused by the impurities present in the solenoid valve that affect the solenoid valve’s synchronization and the electric signal. In addition, the valve core resistance becomes too large to switch along with the electric signals. In this case, you need to disassemble the solenoid valve and clean it thoroughly. Then you should re-install and debug it for better performance. Only follow these steps if you are an expert, as wrong actions can damage the valve.

Reliability and sensitivity action of Solenoid valve

The electric signal plays a significant role in the hydraulic solenoid valve. The operation of the valve depends on the electric signals. If the electric signal is not stable, then the solenoid valve sensitivity can be abnormal, and it can cause fluctuations in the hydraulic operation. In this case, you should look around whether the terminal is poorly connected or not, or the current passing line is too long for causing any voltage drop. If any voltage drop or the terminals are not connected properly, then the electric signal doesn’t transmit to the solenoid valve properly, causing abnormal sensitivity. 

Abnormal behavior of the Hydraulic movement

If there is a fluctuation in the hydraulic operation or there is any performance drop in the hydraulic system, then you should check that the inlet voltage supply to the coil is correct or not. Improper voltage supply can fail the coil and can burn the solenoid coil. Uneven electrical strikes and surges can also damage the coil, so you should always keep an eye on that. And in case the coil is burnt or damaged, you should immediately replace the old coil and put a new one. It would be best if you also kept an eye on the internal parts of the solenoid valve as sediments and unwanted particles can damage the core of the valve, causing abnormal behavior of the hydraulic. 


Solenoid valves are widely used to replace manual valves or in the remote control. Their primary function is to facilitate either opening or closing a valve orifice and regulating the fluid flow through the valve. While the functioning of the valve is somewhat unusual and takes time to adjust to, and what is more important is to learn to troubleshoot a solenoid valve. This article contains all necessary information about the Testing of a Hydraulic Solenoid Valve to check whether it is Ok or faulty! You will get all the answers to your questions with a brief explanation. 

Feature Image Source: Continental Hydraulics

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