With the prevalence of lightweight trend in the semi-trailer industry, the application rate of air suspension is also increasing.

跟传统的悬架相比，空气悬架自重轻、减震效果良好，还能提高车辆行驶平顺性，使车桥实现灵活升降。可相对的，空气悬架价格偏贵且构造复杂，使用中一旦出现问题，很多车主不知道如何去处理。

Generally, whether the air suspension fails can be judged from the following three aspects:

1. The car body is high on one side and low on the other. When encountering bumpy roads, it has a strong sense of vibration and is prone to vibration up and down or body distortion;

2. There is abnormal noise in the car body. Generally, the wind noise on which side will increase sharply if the suspension system on which side has problems;

3. The vehicle deviates, especially when there is a problem with the current wheel suspension system, the direction is easier to deviate, and the direction needs to be constantly corrected.

Once the above three conditions occur, the owner should stop the vehicle nearby and send it for repair in time, or check the vehicle by himself. There are five main reasons for the failure of general air suspension:

1. There is air leakage in the air suspension system or connecting parts;

2. Various sensor faults, such as vehicle height sensor, acceleration sensor, etc;

3. The pneumatic shock absorber is damaged;

4. Air compressor failure;

5. The air suspension control unit or system power supply circuit is faulty.

Some car owners said that after using the air suspension for a period of time, it is easy to have the height difference on both sides. The airbag bridge is high on one side and low on the other. What should be done?

1. Check whether the air bag of the air suspension leaks, and spray it with soapy water. If the air bag leaks, replace the air bag;

2. If there is no air leakage in the airbag, it is necessary to determine whether there is a problem with the vehicle height sensor. You can use a special inspection computer to match it. After matching, check the high and low sensors.

Here, I would like to share with you the height adjustment method of air suspension:

1. Find the horizontal leveling rod, longitudinal leveling rod and leveling valve in the middle of the vehicle axle;

2. Find the fixed nut on the longitudinal leveling valve rod and screw it loose;

3. Move the horizontal leveling rod up (or down), and the height of the airbag will change with the horizontal leveling rod moving up and down;

4. The height of the body raised (or lowered) by the airbag is roughly equal to the height of the saddle, which is the appropriate height after the airbag is adjusted, and then tighten the nuts on the longitudinal leveling rod;

5. If the airbag height is not adjusted to the proper position at this time, adjust the screw fixed on the axle, loosen the nut, adjust the height, and tighten the nut when appropriate.

The air suspension used for semi-trailers can generally be divided into American type and European type, of which the European type can also be called German type. American air suspension guide arm has light dead weight, larger contact area with axle, better lateral support, and is more suitable for use in good road conditions; European air suspension adopts leaf spring guide arm, which has good load-bearing performance, long airbag travel, better shock absorption effect, and is more suitable for domestic transportation environment with complex road conditions and partial heavy load.