The 2007-2008 Mercedes Benz R320 CDI is built with the following rear suspension components:
2007-2008 Mercedes Benz R320 CDI Electronic Shocks (x2)- shocks whose dampening capabilities are controlled by the suspension control module.
2007-2008 Mercedes Benz R320 CDI Air 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.
2007-2008 Mercedes Benz R320 CDI 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.
2007-2008 Mercedes Benz R320 CDI Air Lines- tubes that run from a compressor to the air springs, which carry pressurized air to the air bags.
2007-2008 Mercedes Benz R320 CDI Solenoids (x2)- 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.
2007-2008 Mercedes Benz R320 CDI Compressor Assembly- creates/sends pressurized air 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.
2007-2008 Mercedes Benz R320 CDI Suspension Control Module- a computer which is responsible for the operations of the air suspension system and maintaining the vehicles correct ride height.
2007-2008 Mercedes Benz R320 CDI 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.