Abstract: Hydraulic shock absorber and pneumatic leveling unit for vehicles which incorporates an auxiliary damping device within the pneumatic height adjuster chamber to provide for supplemental damping of vehicle suspension springs by compressing gas in the chamber and restricting gas flow in subdivisions thereof on compression or rebound stroke of the unit.

Abstract: Electrical circuits responsive to a logic signal pair produced when the sprung mass of a motor vehicle is above a selected trim band and to another logic signal pair produced when the sprung mass of the vehicle is below the trim band produce respective sprung mass high and sprung mass low signals for a leveling system of the type operative to level the sprung mass of the vehicle within a predetermined trim band in response thereto. A delay circuit effective to inhibit the production of both the sprung mass high and sprung mass low signals for a predetermined time duration is provided to prevent unnecessary operation of the leveling system and respective accumulator circuits inhibit the production of each the sprung mass high and sprung mass low signals at the conclusion of respective predetermined accumulated periods of time.