The suspension system plays an important role in a car’s operation. It is vital not just in making the car’s occupant comfortable but also in delivering a higher level of safety. The suspension essentially helps in absorbing and directing road force, while supporting the weight of the car. Nowadays, more and more cars employ air suspension systems.
For several decades, the suspension system of most cars employs traditional shock absorbers and coil springs which help minimize the impact transferred from the road to the car, and ultimately to its occupant. However, traditional stock shocks and springs were designed to deal with a limited set of road situations.
Air suspension systems were once exclusive for luxury cars and heavy-duty trucks. However, as ordinary cars get more technological advanced, air bag suspension systems were eventually adopted. Air suspension systems basically replace the coil springs and shocks/struts with air springs, which are essentially air bags made from tough rubber and plastic. The air bags are inflated to a certain pressure and height to function like the coil springs.
Unlike the traditional all-metal suspension systems, air suspension systems are backed by on-board air compressor, sensors and electronic controls, which allows them to be easily customized and adjusted to the driver’s ride preferences. Thanks to these, air suspension systems can adapt the vehicle handling to various road situations, terrain and loads. Moreover, air suspension systems can easily adjust the ride height to adapt to the current ground condition or to make it easier for occupant to enter or exit the car.
Because the air bags of an air suspension system are made from rubber and plastic, they aren’t as heavy duty as their mechanical, metal counterparts. It doesn’t matter if the car is being driven or not, as the air suspension system works all the time. These rubber and plastic bags are subject to wear and tear over time – they become brittle and air would leak. Eventually, the air bags would fail and won't be able work as they supposed to. Furthermore, these air suspension bags could also be damaged from external forces, causing them to fail.
The lifespan of the air suspension bags depends on the manufacturer, the vehicle, their system and how aggressively or conservatively they are used. Each air bag may last between 50,000 and 70,000 miles, or may need a replacement after 10 years.
Meanwhile, you could look out for a number of signs that may indicate that your air suspension bag is already brittle, damaged or failing. These signs include the car sagging on one side, the ride height doesn’t adjust accordingly or the suspension feels softer than usual. Other signs include continuous operation of the air pump, frequent cycling on and off of the air pump, as well as the air bags are needed to be pumped even before the car is driven.