Air Suspension Systems

A vehicle suspension air bag.

In an air suspension system, air bags or air struts replace coil springs and leaf springs. Air bags are often referred to as air springs. Air suspension systems are now found on many makes and models.

Airbags: Airbag failure is typically caused by age and moisture within the system itself. The compressor uses a drier that may become saturated from moisture in the air. This moisture is then passed on to other components in the system. They fail because the rubber dries out, especially at the base where the bag folds. This is a good place to look when inspecting an air bag for leakage. Use soapy water and watch for bubbles on the airbags and air lines.

Solenoids: The solenoids are located at each airbag or strut. They typically suffer from leaks at the connection where the quick-connect o-ring connects to the line. They can leak where the solenoid connects to the air bag. These solenoids are electrical and can have an input or electrical problem. Always follow the manufacturer’s special procedures and specifications.

Air lines: Air lines are made of nylon tubing approved for use in airbag systems by the Department of Transportation (DOT). These lines can become damaged by scraping across sharp chassis and suspension parts as they’re routed throughout the vehicle. Use soapy water if a leak is suspected on route to the problem airbag.

Compressor: The compressors wear in time, especially if there’s a leak in the system. They wear and burn out trying to keep air in the leaking system. Some of these have a failsafe. These newer factory systems are computerized. Use a scanner to retrieve any codes to identify which part of the system to troubleshoot. These connectors are usually located next to the computer in the trunk. In vehicles with air bag suspensions, disable the system with the switch located by the scan connector before raising vehicle.