What Is an Air Suspension System?
An air suspension system is a style of vehicle suspension that's powered by an electric pump or compressor that pumps air into flexible bellows that are typically made out of a textile-reinforced type of rubber. Additionally, Pro Car Mechanics describes air suspension as a replacement to the leaf suspension or coil spring system with airbags composed of polyurethane and rubber. A compressor inflates the bags to a certain pressure in order to behave like springs. Air suspension also differs from hydropneumatic suspension because it uses pressurized air instead of pressurized liquid.
What's the Purpose of an Air Suspension System?
In most cases, air suspension is used to achieve a smooth and constant driving quality, but in some instances, sports suspensions feature an air suspension system too. Similarly, air suspension replaces a conventional steel spring suspension in heavier vehicle applications, like trucks, tractor-trailers, passenger buses, and even passenger trains. Air suspension has also become popular in low-riding trucks like this gorgeous 1982 Dodge D200 Camper Special.
What Is Electronically Controlled Air Suspension?
According to the company now known as Dunlop Systems and Components, at the start of the 1990s, Dunlop developed and installed the Electronic Controlled Air Suspension (ECAS) system on the 1993 Range Rover Classic and again on the Range Rover P38A. The United Kingdom-based company developed the ECAS to include several key features:
Vulcanized, heavy-duty rubber air springs at each of the vehicle's wheels
An air compressor in the vehicle's trunk or under the hood of the vehicle
A storage tank for compressed air, which allows you to store air at around an average of 150 PSI
Valve blocks which direct air to the four springs from the storage reservoir through a set of solenoids, valves, and o-rings
ECAS computer that communicates between the vehicle's main computer to calculate where to direct air pressure
Air pipes connecting from the storage tank to the air springs that channel the flow of air throughout the rear air suspensions system
A desiccant-filled drier canister to keep the internal recesses of the system dry
The electronically controlled air suspension also features height sensors that are based on sensing resistance in contact with the terrain on all four of the vehicle's corners to provide height reference for all corners. Additionally, further advancements are beginning to feature some Electronic Control Units (ECUs) that are able to fit under the vehicle's floorboard, making air suspension more widely featured in everyday driving.