The 2003-2006 Mercedes SL500 is built with the following suspension components:
2003-2006 Mercedes SL500 Active Hydraulic Struts (x4)- -- A long tube (similar to a shock absorber) that fills with hydraulic fluid forced in at varying rates of pressure determined by sensors on the vehicle. The strut is the resting place for a steel coil spring, which works to help support the weight of the vehicle. The struts are known as "active" because they can be adjusted hundreds of times a minute electronically. Much like a shock absorber, the strut dampens vibration and bouncing caused by travel on rough road surfaces.
2003-2006 Mercedes SL500 Height Sensors (x4)- A linkage located near each wheel of a vehicle that electronically 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.
2003-2006 Mercedes SL500 Hydraulic Lines- Tubes that carry hydraulic fluid from a pump to each strut at a high rate of pressure.
2003-2006 Mercedes SL500 Hydraulic Pump - A mechanical pump that delivers hydraulic fluid throughout the system at a high rate of pressure.
On many models, the pump may have a second reservoir that works to deliver power steering to the vehicle. The pump can fail due to normal wear and tear OR it can burn up due to low fluid level caused by leaks in the suspension system.
2003-2006 Mercedes SL500 Suspension Control Module- A computer which is responsible for the operation of the active suspension system and maintaining the vehicle's correct ride height.
2003-2006 Mercedes SL500 Rubber O-rings - Although they are the least expensive part of the air suspension, they are responsible for maintaining the seal where all of the hydraulic lines connect. Be sure to replace the O-rings when repairing any active suspension system.