The 2000-2006 Mercedes S55 is built with the following suspension components:
2000-2006 Mercedes S55 Air Springs (x4)- (models with air suspension only). Commonly referred to as air bags, a plastic and rubber spring that is fitted on top of the strut. The air spring uses pressurized air as a cushion and takes the place of a metal coil spring to support the weight of the vehicle. These rubber air springs are the number one cause of all air suspension leaks. 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.
2000-2006 Mercedes S55 Hydraulic Struts (x4)- (models with hydraulic active suspension). If your model of Mercedes-Benz has this, then the steering pump also pushes hydraulic fluid to your
2000-2006 Mercedes S55 Struts (x4)- a type of shock absorber; has metal tubing filled with gas-charged hydraulic fluid that is connected to the wheel of a vehicle in order to reduce the effects of vertical travel on a rough surface which controls the bounciness, and therefore comfort, of a vehicle.
2000-2006 Mercedes S55 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.
2000-2006 Mercedes S55 Air/Hydraulic Lines- tubes that run from a compressor to the air struts (or a hydraulic pump to the hydraulic struts for models with hydraulic active suspension), which carry pressurized air to the air bags (or hydraulic fluid to hydraulic struts) in order to adjust the height of the vehicle, respectively.
2000-2006 Mercedes S55 Solenoids (x4)- usually L-shaped, these plastic components connect the electrical connection and lines of suspension components to the suspension control module on vehicles with active suspension. The solenoid regulates the air pressure for each air spring. Solenoids start to leak as they wear out causing the vehicle to sag or to lean. This will cause the ride height sensor to send a signal to activate the compressor in an attempt to inflate the air suspension and level out the vehicle. This excessive work load will eventually lead to total failure of the compressor.
2000-2006 Mercedes S55 Compressor Assembly- (models with air suspension only). Creates/sends pressurized to active suspension components. When the air suspension starts leaking, the compressor/pump starts working harder to try to keep the system inflated. By the time air suspension leaks down completely, sitting the vehicle on its tires, the compressor will either have failed or be well on its way to full failure. Buying replacement struts and taking the time to install them only to find out the compressor still needs to be replaced can be very frustrating, time-consuming, and expensive.
2000-2006 Mercedes S55 Hydraulic Pump- if your Mercedes has hydraulic suspension (Active Body Control) instead of air suspension, then the hydraulic steering pump will also serve as the reservoir for the hydraulic fluid going into the struts.
2000-2006 Mercedes S55 Suspension Control Module- a computer which is responsible for the operations of the air suspension system and maintaining the vehicle's correct ride height.
2000-2006 Mercedes S55 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 or hydraulic lines connect. Be sure to replace the O-rings when repairing any air suspension system.