1994 E320 Estate Self Leveling Suspension Troubles - PeachParts Mercedes-Benz Forum

little_e · #1 04-30-2011, 01:11 PM

My 1994 E320 Estate has about 181500 miles on the clock. It's not a Sportline, but it has the sportline suspension (option code 653).

When the car sits unladen, it looks okay. It's not one of those old w124 cars that looks jacked up in the rear, nor does it look like it has a rhino in the trunk.

When I drive the car over a small bump in the road the rear suspension feels very firm, just like my Audi with sport suspension and Bilstein B8's.
...but when I drive over a larger bump, a speedbump or drive fast over speedbumps (like 27-28 mph) it feels like the rear suspension is like.. a sponge.

For the record, there's no funny noises, clunks, clanks, bangs and dings from either the front or rear suspension. I haven't lost any hydraulic oil.

What's most likely to be on the blink? Suspension spheres or the self leveling shocks themselves?

kwontumspeed · #2 04-30-2011, 03:43 PM

If there aren't any leaks anywhere in the system, it's most likely your spheres.

babymog · #3 04-30-2011, 03:48 PM

If the shocks (dampers) are shot, they usually leak. With enough miles or hard use they can lose damping ability, but gradually.

It sounds like (as KW said) a sphere or spheres are failing. In the early states this lets nitrogen into the fluid, and the dampers are unable to damp the motion properly as they are designed for hydraulic oil, not gas and bubbles.

As they get worse, you will lose a little fluid into the spheres (not external leaks), but what you will notice more is that the car rides like a truck in the rear, because the dampers will become hydrolocked (nowhere for the fluid to go on jounce/compression).

A little bit of a tedious replacement job, probably is a DIY sticky, and about $80/side for the spheres IIRC but definately a DIY. Be sure to get the 4 crush-washers for the sphere to banjo-bolt connection and a liter of fluid when you order spheres (accumulators).