Air springs have been used in heavy duty vehicle suspension systems for nearly a century, where they have been able to provide usefulness by taking advantage of the compressed air required for vehicle braking systems. Air springs have provided a two-fold advantage over mechanical leaf- or coil-springs. One advantage with air suspension is the extra comfort provided by being able to vary the air pressure inside the spring, which changes the spring rate, and therefore, ride quality. Additionally, because variable control over air pressure adjusts the deck or trailer height, aligning loading docks to the level of the deck is possible when dock plates are unavailable.