Firestone air springs ‘assist’ your existing suspension by distributing the load between the chassis and the leaf or coil springs and axel. There could be several reasons your air springs aren’t raising your vehicle to its standard ride height. Your vehicle may be overloaded with too much weight and you may have reached the maximum pressure of the air springs specified. Furthermore, if your current leaf or coil spring suspension is too old and has sagged over time, this can cause the air springs to bear most of the load preventing you from reaching your standard ride height position.