In automotive applications, air suspension systems typically incorporate a series of air bags into the suspension system. These bags can take the place of traditional components, like springs, or serve to assist them. In some heavy-duty applications, an air suspension can help take some of the stress off the traditional suspension parts. In either case, the air bags will typically have the same type of Schrader® valves found in car tires, and can be checked and filled with the same tool used on tires. If the air bags fail, the vehicle may become difficult, or even dangerous, to operate.
Some vehicles come from the factory with an air suspension, while others are customized prior to the customer purchasing the vehicle. An example of this could be a recreational vehicle (RV), where the RV manufacturer purchases bare chassis from the vehicle makers. In addition to building an RV on the chassis, these types of customizers may add equipment like an air suspension or track bars, to improve handling and safety.
In many cases, it is possible for a vehicle owner to install his own custom air suspension. The necessary parts to accomplish this are often available in the aftermarket. Depending on the owner's expertise, he may install the custom parts on his own or can opt to hire a professional mechanic to perform the work. An aftermarket air suspension like this may be designed simply to improve handling, or can be part of a lift kit meant to raise the vehicle body up off the frame. The latter can be either for aesthetic purposes, or to increase ground clearance on a vehicle that will be driven in off-road conditions.
Air bags in these suspension systems tend to lose air slowly, in a manner similar to tires. This can make it important to check the air in them on a regular basis, as driving with flat air bags can cause them damage. In some cases, each air bag will have a Schrader® valve that must be checked at the air bag, while others will use tubes to route all the valves to a central location.
Some air suspension systems are automatic. These types can include an on-board air pump that automatically fills the air bags to the specified level each time the vehicle is started. If a vehicle is equipped with one of these automatic systems, it may be important to ensure the air bags have deflated before jacking up the vehicle for service. Failing to do so can potentially cause damage to the air bag system.