Mercedes-Benz S210 rear end bouncing and level control spheres
Why does the S210 rear end bounce over bumps?
The most common cause is the level control gas spheres. When the diaphragm or gas of a sphere has failed, the level and suspension of the whole rear axle suffer. There are two spheres. A leaking or worn rear shock absorber can also make the rear end unsettled.
Can the hydraulic oil level cause bouncing?
Yes. If the oil level is below the minimum, for example after a shock absorber replacement, the level control does not work properly and the rear end bounces. Topping up the fluid to the correct level can fix the symptom. Check the oil level before replacing the spheres.
How are the level control spheres replaced?
The spheres are clearly visible under the car. The pipe connections should be soaked with rust penetrant beforehand, and seized connections must not be forced. After the replacement, oil is added to the reservoir, and the level is checked after a few kilometres of driving. The system is pressurised, so oil may splash when opening the connections.
When should the job be left to a workshop?
If the pipe connections are badly seized, the pipes are rusted or the job grows larger, let a workshop do it. The condition of the rust or structure is assessed by the workshop. The hydraulic pipes can be made or repaired at a hydraulics shop if necessary.