The 1996-1999 Mercedes Benz S420 RWD is built with the following suspension components:
1996-1999 Mercedes Benz S420 RWD Hydro-Pneumatic 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.
1996-1999 Mercedes Benz S420 RWD Electronic Shocks (x2)- shocks whose dampening capabilities are controlled by the suspension control module.
1996-1999 Mercedes Benz S420 RWD Height Sensors (x2)- 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.
1996-1999 Mercedes Benz S420 RWD Compressor- This vehicle is equipped with one air suspension compressor. The compressor is responsible for pumping up the air springs and shocks. When the air suspension starts leaking, the compressor is forced to run continuously to try and keep the air springs inflated. After a couple of days of running non-stop, the compressor will burn itself out. Replacing the compressor is a timely and expensive project to undertake.
1996-1999 Mercedes Benz S420 RWD Dryer Assembly- This vehicle is equipped with a dryer assembly. The dryer assembly is responsible for getting moisture out of the air lines. Once the air suspension parts start to leak, moisture will build up throughout the air system. Moisture damages the air suspension components from the inside out. The dryer must be replaced whenever the compressor is replaced to prevent further damage.
1996-1999 Mercedes Benz S420 RWD 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.
1996-1999 Mercedes Benz S420 RWD 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.
