Need to know more about rear suspension in W140's - PeachParts Mercedes-Benz Forum

pcmaher · #1 08-16-2004, 11:17 AM

I did a search with no results for what I'm looking for. I finished putting new accumulators into the rear of my 95 S600. I am disappointed that the ride is not as soft as I had anticipated. It seems less bouncy than before, but I'm not certain yet. I have to drive it more. I would have thought that if I had bad accumulators (which I'm pretty sure I did), the ride would be much smoother with the new accumulators.

I'm looking at other components now to see if there are any other problems. Can anyone explain the function of the damper valve assemblies? They are in line between the axle height supply valve and the struts. I assume these are the valves that firm up the ride when firm mode is selected. Do these valves restrict the flow of hydraulic oil to provide a firmer ride? How are these valves tested to evalute if they are functioning properly?

I wonder if I'm being too critical of the ride quality. Is there anyone in the Chicago area with a W140 willing to drive me around in their car so I can compare ride quality?

myarmar · #2 08-16-2004, 07:32 PM

That's what I found on ADS damping valves:

pcmaher · #3 08-16-2004, 07:50 PM

myarmar,

Thanks a bunch. This makes sense. I understand the operation now. Please tell me what year(s) and model(s) this diagram represents. The damper valve assemblies on my 95 S600 do not look like this. I also see 4 settings listed, my car has only soft or firm. Does anyone know if these dampers send out a code if they are faulty? I have no ADS caution light on, but I may try to hook up the 'ol code reader to see what's in there.

Hatterasguy · #4 08-16-2004, 07:59 PM

My friend's dad has a 1995 S600, I'll see if I can get him to chime in but it seems to ride just perfectly. His has 18in amg wheels on it with low profile tires and in comfort mode it just glides, you feel a few bumps but it does not bounce. In sport mode it rides more stiff but not bouncy.

myarmar · #5 08-17-2004, 12:30 AM

pcmaher,

The picture above came from MB Education for Excellence CD and I believe is a generic ADS description. The 4 settings of the damping valves not to be confused with 2 settings of the switch. You can select comfort of sport setting from the switch, but this is just one of the inputs to ADS control module N51. It also gets signals from suspension acceleration sensor, body acceleration sensor, steering angle sensor, and the switch. Based on these inputs it selects one of the 4 settings for damping valves. Two rear valves are in parallel, but front valves can be controled individually by ADS control module. I don't know if 95 has same system.