A suspension air spring lift kit has a trailing arm having an end that is pivotally connected to a hanger bracket. A vertically oriented air bag is connected between another end of the trailing arm and a frame member of a vehicle, for example, a dump truck or a trailer in a tractor-trailer combination. An air spring system having a lower bracket and an upper bracket, with an air spring bag positioned between these two brackets, is attached between the frame member and the trailing arm. When the air spring bag is inflated, the air spring system lifts the trailing arm. When the air spring bag is deflated, the air spring system allows the trailing arm to be lowered.