What are common faults with air suspension?

What are common faults with air suspension?
Do you love the incredibly smooth ride of an air suspension system but dread the day it might fail? A fault in the system can leave your car grounded and unable to be driven, and the thought of a complex and expensive repair is intimidating for any owner.

The most common faults with air suspension systems are air leaks from worn-out rubber air springs (also known as airbags), leaks from cracked or damaged air lines, a failing air compressor that can no longer build enough pressure, and malfunctioning ride height sensors that give incorrect information to the system’s computer.

As a parts supplier that stocks a wide range of air suspension components for European and luxury cars, I’ve seen every one of these faults firsthand. While air ride offers a level of comfort that is second to none, it is a complex system with more potential failure points than a traditional steel spring setup. Understanding these common faults is the first step to being able to diagnose and fix them efficiently. Let’s explore some of the key questions surrounding these sophisticated systems.

What parts do I need for air suspension?

You’re looking to repair a faulty system or perhaps install a custom air suspension kit, but the list of required parts is long and confusing. Ordering the wrong components for a job this complex is a very costly and time-consuming mistake.

A complete air suspension system requires four air springs (often integrated into air struts), an electric air compressor, an air tank to store pressure, a valve block or manifold to direct the air, an electronic control unit (ECU) to act as the brain, ride height sensors, and all the necessary high-pressure air lines and fittings.

It helps to think of the system in functional groups.

The Core Components

• The Springs: These are the flexible rubber air springs (also called airbags or bellows). In most modern cars, they are integrated into a complete air strut, which also includes a built-in shock absorber. These units replace the traditional coil spring and strut assembly.
• The Air Supply: This consists of the air compressor, an electric pump that generates the high-pressure air, and the air tank, which stores this compressed air so the system can make quick height adjustments without having to wait for the compressor every time.
• The Brains & Nerves: This is the Electronic Control Unit (ECU), which is the computer that runs the entire system. It receives information from the ride height sensors located at each wheel. Based on these readings, the ECU tells the valve block (or manifold) which air spring to inflate or deflate.
• The Connections: All of these components are connected by a network of high-pressure air lines and specialized fittings. As a parts warehouse, we supply all of these items, from complete air struts to individual compressors and valve blocks, because we know a repair might involve just one part or the entire system.

How much does it cost to fix an airbag suspension?

Your car’s "Suspension Fault" warning light is on, and you’re bracing for a massive repair bill. The perceived high cost of air suspension repair makes many drivers nervous about owning these otherwise very comfortable cars.

In Singapore, the cost to fix an air suspension system can range from S$800 – S$1,500 to replace a single leaking air spring on a common model, all the way up to over S$4,000 to replace a failed air compressor and valve block on a high-end luxury vehicle. The cost depends entirely on which specific part has failed and the vehicle’s make and model.

Let’s look at the costs of a few common repair scenarios.

Common Repair Scenarios

• Single Air Spring Replacement: This is the most common repair. If one corner of the car is sagging low overnight, you likely have a leak in that corner’s air spring or strut. The part itself is the main cost of this repair.
• Compressor Replacement: If the compressor burns out, the car won’t be able to generate any air to lift itself. This often happens because the compressor has been running too long trying to compensate for a leak in the system. This is a more expensive part to replace than a single air spring.
• Valve Block or Sensor Failure: These electronic parts are less common failures but can be tricky to diagnose and can be costly to replace.

Aftermarket vs. OEM Costs

This is where a good parts warehouse makes a huge difference for workshops and car owners. An original OEM air strut from an agent for a Mercedes or BMW can be incredibly expensive. We source high-quality aftermarket air struts from reputable global manufacturers that can cut that part cost by 30-50% or more, without sacrificing reliability or ride quality. This allows workshops to offer a much more affordable repair, making it a viable option instead of scrapping an older but otherwise good luxury car.

How long do air suspensions last?

You are considering buying a car equipped with air suspension but are worried about its long-term reliability. How long can you expect the system to be trouble-free before you might have to face those potentially expensive repairs?

The main wear components of an air suspension system, which are the rubber air springs, typically last about 8 to 10 years, or around 100,000 to 150,000 kilometers. The compressor and other electronic components can have a similar lifespan, but their failure is very often linked to un-repaired leaks in the system.

Let’s discuss the factors that affect the lifespan of these systems, especially here in our local climate.

The Lifespan of Rubber

The air springs are almost always the first point of failure as the system ages. They are made of a flexible, multi-layered rubber compound that is constantly flexing and moving. Over many years of this movement and being exposed to the elements, the rubber naturally degrades. It becomes more brittle and develops tiny, microscopic cracks, which eventually grow large enough to cause air leaks. Here in Singapore, the constant high heat and humidity can accelerate this aging process significantly, making regular inspections very important as a car approaches the 8-year mark.

The Domino Effect on Other Parts

A small, slow leak in an air spring¹ can drastically shorten the life of the air compressor. The leak forces the compressor to run much more often and for longer periods to keep the system pressurized. This can cause the compressor to overheat and burn out prematurely. This is why it is so important to fix air leaks² as soon as they are detected. A small, relatively inexpensive repair today can prevent a much more expensive one tomorrow. This is critical advice we always give to our workshop clients.

What are the downsides of air suspension?

Air suspension offers an amazing, cloud-like ride, but for some, it seems almost too good to be true. Before you buy a car that has it or decide to install a custom kit, what are the potential disadvantages that you should be aware of?

The main downsides of air suspension are its complexity, its higher initial and repair costs, and its potential for a complete failure. With compressors, sensors, air lines, and a computer, there are simply more things that can go wrong compared to a simple coil spring. A single failure, like a major leak, can also render the vehicle completely undrivable.

It’s helpful to weigh the good against the bad.

Weighing the Pros and Cons

Is It Worth It?

For many people, the answer is a resounding yes. The incredible comfort and versatility are worth the trade-off in complexity and potential cost. For a luxury vehicle, it’s a core part of the premium experience. For a custom car, the height adjustability³ is the main appeal. As a parts supplier, our main goal is to mitigate the biggest "con"—the high repair cost. By providing high-quality aftermarket alternatives for air struts, compressors, and valve blocks, we make owning and maintaining these incredible systems much more affordable and less intimidating for the average car owner.

Conclusion

An air suspension’s most common faults are air leaks and compressor failure. While its complexity leads to higher potential repair costs and a finite lifespan, its superior comfort and adjustability are benefits that are hard to beat for many drivers.Choose GSW to safeguard your needs.