Self Leveling Suspension

Vehicles with rear load leveling such as the W140 (S class), W210 (E class wagon), W124 (E class wagon) have nitrogen accumulators that act as suspension dampeners. If you notice the rear sagging down, harsh over bumps or the ride oscillating over bumps the rear accumulators may have failed releasing the nitrogen gas charge into the hydraulic fluid. As a result the suspension fluid becomes compressible and the ride height cannot be maintained. If the gas is expelled the ride will be very hard due to a lack of dampening. The rear shocks get worn and can start to leak, and the suspension lines can become corroded. The rear suspension on these vehicles needs to be carefully evaluated before commencing repairs. Due to corrosion shock and lines may have to be replaced when doing the accumulators because lines cannot be separated.