Expedition 4WD V8-4.6L SOHC VIN W (1999)
Air Spring: Description and Operation
Front Air Shock Absorbers
Adjustable air shock absorbers are used for the 4WAS system vehicles. Enclosed in each shock absorber is an air spring. Replace a faulty shock
absorber as a unit.
The air spring integrated into each air shock is capable of independently raising and lowering each corner of the vehicle based upon the pressure and
volume of air supplied. The air suspension system regulates the pressure in each air shock by compressing and venting system air. Increasing air
pressure (compressing) raises the vehicle and increases the total spring rate (spring effect of the air shock plus the front torsion bar) of the wheel being
modified. Conversely, decreasing air pressure (venting) lowers the vehicle and effective spring rate. Vehicle height is then maintained by the addition
and removal of air in each air shock.
