Compressed air from a service station or with any air compressor is added in chamber of the each shock absorber, which lifts the rear side of the vehicle. Self or automatic leveling system is also available as an option on many automobiles. It automatically maintains the correct rear height as weight is added or removed from the automobile. This system consist of a vacuum operated compressor, a height control value, two air cylinders, connecting lines and fittings.
The compressor fitted in the engine compartment air under pressure to operate the air cylinder. The compressor is operated by engine vacuum and atmosphere pressure. The height control Valve mounted on the flame cross member senses the rear end height through a linked connected to the rear suspension upper aim. The valve works whenever the body lowers or rises due to change in weight.
When added weight lowers the body, the link counter the valve to move to its intake position, which permits air from the compressor to enter the air cylinders and raise the body. When the weight removed the body rises and the link reverses the action of valve. Aim is released from the cylinders through an exhaust port in the valve. A time delay mechanism built into height control valve prevents the transfer of air to and from the cylinder in normal ride movements. The rubber air cylinders are mounted inside the rear spring.