An air-suspension system is used to replace coil springs in an automobile, traditionally used to absorb shock and provide a smoother ride, with air springs made of heavy-duty rubber. They use onboard compressors, airbags, solenoids, valves and lines to balance heavy payloads and improve a vehicle's ride. As of 2014, air-suspension systems offer distinct advantages over metal springs, including instant tuning, improved suspension and adaptability to different driving situations.
In newer vehicles, this automotive technology offers more control and easier installation than conventional springs. In air-suspension systems, air bags replace coil springs and the airbag is inflated to the appropriate ride height. The system uses an onboard compressor, which is an electric pump, to feed air to the bags through multiple lines. The compressor pulls outside air into the pump, compresses the air and transfers it to the bags. Valves are used in the system to allow air to enter different parts of the system. Valves play a major role in controlling the direction of the air. Solenoids are useful for inflating and venting the airbags in electronically controlled systems. When the system makes adjustments for different driving conditions, the solenoids open and close to change the amount of air entering each airbag. In electronic systems, there is an electronic control module that controls the analog on/off controls, manages ride height and monitors pressure.