The 1998-2002 Mercedes E320 Wagon is built with the following suspension components:
1998-2002 Mercedes E320 Wagon Air/Hydrualic Springs (x2)- Commonly referred to as air bags, a plastic and rubber bag that is fitted on top of the strut that uses pressurized air as a cushion instead of a metal coil spring to hold a vehicle off of the ground and off of its wheels. These are the number one cause of all air suspension leaks. All air springs all go bad at about the same rate. If one is leaking, the others will not be far behind. For a proper repair, all of them need to be replaced at the same time. If your model has hydraulic springs/struts, then it is filled with hydraulic fluid instead of air to adjust the height and dampening of the vehicle.
1998-2002 Mercedes E320 Wagon Electronic Shocks (x2)- shocks whose dampening capabilities are controlled by the suspension control module.
1998-2002 Mercedes E320 Wagon Height Sensors (x4)- a linkage located near each wheel of a vehicle with any electronic suspension that, either mechanically or electronically, constantly measures the height of the vehicle, and reports this information back to the control module so that the computer can identify if changes in height need to be adjusted accordingly. The ride height sensor is a moving part, and like all moving parts, they will eventually wear out.
1998-2002 Mercedes E320 Wagon Suspension Control Module- This vehicle is equipped with a suspension control module. This module is the brain of the suspension system and it reads all of the signals that are being sent by the height sensors and determines if the vehicle needs to be raised or lowered.
1998-2002 Mercedes E320 Wagon O-rings- Although they are the least expensive parts of the air suspension, they are responsible for maintaining the seal where all of the air lines connect. Be sure to replace the O-rings when repairing any air suspension system.