According to other posts in this forum, MB's self-leveling system is a maze one should fear to rush into. However, when its broken it needs to be fixed. So any advice is much appreciated regarding my poor '90 300TE. My findings:

• The different SLS lines are in bad shape ie rust is an issue with this car
• When I push down the front of the car, it dips an inch and has only one rebound
• When I try to push down the rear of the car, it dips only a fraction of an inch, has a quick rebound and then bounces about five times per second until the movement dies, ie no shock absorption
• The suspension has this behavior uniformly on both sides of the car
• It behaves like this regardless of the engine is running or not
• There is oil in the reservoir, the oil filter is clean and the drive belt is tight
• The car does not seem to have turned into a lowrider, the rear seems to keep its height. I don't know how much the SLS makes the car lose height if it gets broken, but I believe I would notice the difference of, let's say, two inches.
• Hmm... The problem started during our 3000 mile drive to the French Riviera this summer, and there was this French mechanic who fixed the A/C. He did something to the wiring in the right front of the engine compartment in order to make the A/C work. And yes he fixed the A/C alright. But then again, it might be coincidence.

I have studied MB's workshop manual, and the test procedure for the SLS feels like a mile long, and it requires both pressure testing tools and a facility where one can get under the car while its wheels are on the ground. Oh. Anybody out there who has any advice on a simpler testing procedure, or who knows what may be causing this?

Regards,

/Jan

I found an interesting thread after I made the above post (how come they never show up before?): http://www.peachparts.com/shopforum/showthread.php?t=4912&referrerid=6198. In it, the accumulators are accused of being the source of trouble. Does anybody know why they would both break at the same time?

Because they're the same age and have been subjected to the same use.

__________________
Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

I think you most likely need new Air bags in the rear. My friends 560SEL had that same jarring rough suspension in the back. He replaced the airbags and they were smooth again. The mech said that the hydraulic fluid should be changed often to prevent the air bags and other SLS components from wearing out too early caused by dirt.

Thanks, guys. I remember a Yamaha Virago bike I bought in the 80's. After about two years one of its horns stopped working, and two weeks later the other one broke down too. Now that's what I call uniform quality. In the case of the accumulators, if one breaks down perhaps the other one gets a heavier load and breaks because of that?

Does anybody see any faults in the following reasoning? The accumulators suspend the hydraulic system. And without suspension in the accumulators, the struts do not work as dampers because they need to deposit fluid in the accumulators. And with the hydraulic suspension system frozen, the mechanical springs won't work either. And without proper suspension in the rear of my car, something far more expensive than the accumulators will eventually break and so will the owner's economy.

the accumulator spheres are pressurized nitrogen on one side and hydraulic fluid on the other. The fluid and gas are separated by a rubber diaphragm. The diaphragm flexing gives the car its spring characteristic. The hydraulic ram (shock) gives the car its damping ability.

When the rubber diaphragm breaks, the accumulator is filled with fluid and being non-compressible, gives the rock-hard ride.

For a good graphic of the hydropneumatic system, visit the m-100 site:
www.m-100.cc

Look at the Hydro system in the 6.9. The principles are the same for a TE.

Thanks for your advice, guys. I will replace the accumulators and report back.