Air suspension problems

Some luxury cars and even trucks are equiped with air suspension systems. They enhance comfort on bumpy roads. The comfort that they offer is beyond what a spring suspension system offer. Unfortunately, the air suspension system is not without its problems as they are prone to failure through different ways. Vehicles with air suspension use dampers just like every other vehicle but they use air balloons instead of coil springs.

This is what makes them to be more comfortable. The air suspension system in Mercedes benz is known as airmatic suspension.

Most air suspension systems are adaptive in the sense that they adjust their ride heights depending on vehicle speed and road condition. The ballons also known as the air springs are inflated by the air compressor through the valve block.

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Symptoms of faulty air suspension

1. Vehicle sagging or excessively lowered ride height.

2. Vehicle stuck at maximum possible height.

3. Unequal heights between the wheels.

5. No ride height adjustment.

6. Excessive priming of the air compressor.

7. Bouncy ride.

Common air suspension faults

These systems have popular fault areas. These are what make them quite unreliable.

1. Leaking balloon

This occurs when the balloon is punctured or has deteriorated over time. Low quality ballons in the market are more susceptible to leaking early.

2. Balloon explosion

This is when the balloon explodes with a loud bang that is similar to a gunshot. Over inflation or deterioration are the major causes of explosion.

3. Faulty ride height sensor

Ride height sensors are located at each wheel of the vehicle and they send height signals to the control unit of the air suspension. A faulty ride height sensor that sends a wrong signal can cause the vehicle to sag or cause the air spring to over inflate which can cause it to burst.

4. Bad fuse

The air suspension electrical system is protected by fuse(s). When a fuse goes bad, the system will not function.

5. Faulty air compressor

The air compressor compresses air to inflate the balloons at each of the wheels. When there is leak in the system, the compressor works too hard to keep the balloons pressurized. This makes it to overheat and get damaged prematurely.

6. Faulty valve block

The valve block controls air inflation and pressure at each wheel. The valves work in open and close states. There are also pressure relief valves that releases pressure from the system. The air that enters the compressor and valve block is filtered to avoid dust and other debris from getting in. When dust or other debris enter the valve block, they may cause the valves to stick, not open or close properly.

7. Faulty plumbing

Air is supplied to the air springs through small flexible tubes and are terminated on the air spring at each wheel. The tubes/hoses can cut, rupture or have small leaks. The termination points can also leak. A simple way to test for leak at this point is to pour water when the balloon is inflated to see whether bubbles will come out.

8. Bad O-rings

There are O-rings that make the air spring to be air tight. They serve as seal between the air spring that moves along the damper (shock absorber). Where the hoses that supplies air to the balloon are terminated, there are tiny O-rings that are meant to prevent air leakage.

9. Wrong calibration

The system works with calibrated height values of each wheel. If calibration is not done or not done properly by ensuring that the vehicle is on a levelled surface, the air suspension system will malfunction.

10. Bad control unit

Having a bad control unit that controls the air suspension is rare but it does happen.

11. Bad relay

A bad air suspension relay will cause the system not to function.

12. Bad dampers

Dampers that are weak or completely bad will increase the stress and strain on the air spring which can cause early failure.

13. Bad wirings, connectors and plugs

Wires and electrical connectors that plug into the air compressor and valve block can cause problems if there is partial contact.

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Safety precautions with air suspensions

1. Allow only competent technicians to handle a vehicle equipped with air suspension.

2. Deflate the system before carrying out maintenance on it.

3. Isolate the air supply and remove the fuse/relay before working on it.

4. Don't rely on air suspension for maintaining vehicle height if you are to work under the vehicle.

5. Do not inflate the air suspension completely while the vehicle is still on jack stand.

6. Carry out visual inspection of the balloons from time to time.