For 1990-2009 cars

The rear air adjustable shock absorbers are constructed with a rubber-like air sleeve attached to the dust tube and reservoir. This sleeve forms a flexible chamber which extends the shock absorber when pressure in the chamber is increased. When air pressure is reduced, the weight of the vehicle collapses the shock absorber. In order to maintain proper operation and reliability of the air adjustable shock absorbers, a system pressure from 48-97 kPa (7-14 psi) must be maintained at all times.