W124 Estate Self Levelling Suspension

[hotrodder]

Doesn't sound like the seller, his mechanic or the MOT guy understand how the system works.

The 'shock absorbers' are actually hydraulic rams/struts and the damping (along with much of the 'springing') is handled by Citroenesque spheres. As said, the system differs from the Citroen in that it also has coil springs too.

A hard/bouncy ride is the classic symptom of knackered spheres... over time the nitrogen leaks out and/or the diaphram that seperates the gas from the hydraulic oil splits. Result is a loss of damping and compliance in the suspension. They won't cause a scrapping noise but there's plenty of other things that could...
Sphere's themselves typically last for around 100k miles max and are around £60/70 - £90ea depending on source. There's an access panel in the boot floor immediately behind the back seats and ahead of the third row seats/under floor compartment. Corrosion to the hard lines (as well as fuel and brake pipes) and unions is common, particularly around the back axle where access to replace them is complicated by the subframe

Your best bet would be to have the car looked at by an MB specialist/indie as many mechanics won't be familiar with the suspension layout on these

 

[Richard Elliot]

well its probably not the springs then, but something in the hydraulics. Nothing simple like shock absorbers I'm afraid...

 

[firstmerc]

How hard is to the replace the spheres for a diyer?

 

[hotrodder]

Somewhere on this forum (or the other one) there should be a DIY article or thread on the subject i think. It's not rocket science but i wouldn't describe it as a beginners job... it's an access/fiddlyness thing really, think potential for rounding off unions/cross threading things. Given what you've already been told about the rusty fluid pipe(s) it's likely there'll more to do than just changing the spheres.

Mine needed doing last year but as i was able to blag use of a proper 2 post lift i decided to drop the rear subframe and deal with 'everything' in the area- replaced the spheres, brake/fuel/suspension lines (all were rusty and on their last legs), subframe bushes and cleaned up everything in the vicinity that's a ballache to get to with the subframe fitted. With the subframe out access is brilliant but dropping the subframe ain't a small job outside of a proper workshop, it's 'kin heavy for one thing.

 

[balge59]

How hard is to the replace the spheres for a diyer?

Hi
did it on my 230TE, not too much of a problem - I've spannered on old motorbikes a lot, but never worked under a car before, managed ok even with only a Haynes...
If you have any rusty pipes I would seriously consider replacing them while your at it. The short ones are only a few quid.As said it's a bit fiddly but straight forward IF you can get good access, had mine on decent ramps which was just adequate.
Found that my replacement spheres needed extra washers as the studs were not threaded all the way down, so when I torqued them down they rattled...Might be worth flushing the fluid while you're at it too.

I think your car sounds like it is sitting quite low compared to either of my T's, worth checking the springs aren't tired (they break fairly often, mainly fronts though )- check the back box for scratches underneath? ( Although that can be tired mounting rubbers...ask me how I know...:Oops
cheers

 

[Rockall]

Spheres etc

As an ex Citroen owner - 3 Xm's and 1 Xantia all of which managed to do inter galactic mileages for me whilst I was cosetted in supreme comfort - may I make a few comments on self levelling suspension and the maintenance of same. I am not familiar with the setup on Mercedes but the principal will still apply.

1: Cleanliness is of utmost importance - if doing any work at all treat the pieces as if an operating theatre. Microscopic dirt can play havoc with valves etc.

2: Change the suspension fluid regularly, it is like any oil or fluid it has a life span and is not expensive. I used to flush out my XM's system every 50,000 with special flushing fluid and then replace with fresh fluid.

3: The gas in the spheres eventually weeps through the membranes - I was able to get the Citroen spheres regassed for a few pounds at the time - great improvement to ride quality. Also include the central accumulator in this service. Depressuring the system was a 90 second job - undo a small valve.

4: Keep the actual self levelling levers and valve system well lubricated as they can seize or get stiff and will have a noticeable effect on ride quality and height.

Most times bad ride quality is because of spheres - low gas pressure or at worst burst membrane. Either re-gas or replace. Also check the actuating system linkage for rust or seizure. If replacing spheres always change fluid as well. I never had a ram or strut give trouble. All in all it is actually a very simple and reliable system once you understand how it works and more importantly how to service it - most garages walk away!!
Rolls Royce, Jaguar, BMW and of course Mercedes have all used part of the Citroen system but somewhere along the way the servicing of the system by these garages seems to get lost.

Best regards

Bill

 

[television]

Thank you Bill very much for the above advice .

I had 8 CX's wonderful cars

 

[TripleP]

Hi, just reading this and it has prompted me to ask a question :-

My 200te just feels a bit firmer than usual,it goes up and down,but doesn't
seem to be soaking up the bumps like it used to, could it be the spheres that need replacing?
I did quite a bit of work on a citroen BX a number of years ago and replaced quite a few parts,but it was necessary to de pressurise the system via the master sphere before carrying out any work.Is it the same procedure on the Mercedes.And lastly what would you recommend re replacement spheres
MB or pattern.I bought most of the parts for the Citroen from a hydraulic
specialist called Pleides in Cambs.

Thanks

 

[hotrodder]

My 200te just feels a bit firmer than usual,it goes up and down,but doesn't
seem to be soaking up the bumps like it used to, could it be the spheres that need replacing?

Sounds like they could be on their way out... they only get properly bouncy/rock hard when pretty much all the nitrogen has dissappeared and/or the membrane ruptures i.e. the space for gas spring gets replaced with hydraulic fluid

I did quite a bit of work on a citroen BX a number of years ago and replaced quite a few parts,but it was necessary to de pressurise the system via the master sphere before carrying out any work.Is it the same procedure on the Mercedes.And lastly what would you recommend re replacement spheres
MB or pattern.I bought most of the parts for the Citroen from a hydraulic
specialist called Pleides in Cambs.

Thanks

There is no master sphere on these, no need as they have conventional brakes and springs to support the car when the engine isn't running. The fluid is slightly different too, goes by the name ZHM
MB don't make spheres. I dunno whether their usual source was Lemforder (iirc these are what Euro car parts supply) or Febi. When i replaced mine i bought Febi ones from Wunderpartz- very friendly, helpful and a fair bit cheaper than all the other usual suspects at the time.

 

[Rockall]

Bouncy

Just spotted your question re 200. From my years of Citroen's - yes, the gas has escaped from your spheres. I am not familiar with the actual set up on the Mercedes but there has to be some valve to allow system pressure to be released otherwise removal of spheres will be very difficult. If your spheres are not that old, one option would be looking at getting them re-gassed - maybe some of your old Citroen contacts could help you there.
If spheres are old - bite the bullet and fit new ones would be my recommendation.

Regards

Bill

 

[hotrodder]

While it's similar in principle the MB set up is different to Citroen regarding the details for example the spheres are bolted to the car with a seperate hydraulic union. More here... http://www.w124performance.com/service/w124CD2/Program/Chassis/32-0501.pdf and sphere replacement details here... http://www.w124performance.com/service/w124CD2/Program/Chassis/32-0620.pdf

I haven't read through them but from memory they don't mention depressuring things although the level corrector can be used to minimise fluid spills by moving it manually and making use of it's bleed nipple (not one you want to break though as the valves are 'kin pricey!!)

 

[Rockall]

spheres

Great diagrams - interested to see that the 190 (w201) was available with spheres front and back - does anybody know which model that was?

 

[TripleP]

thanks guys,replies much appreciated

 

[davidp]

rear suspension

Hi
not sure if any one can help but my suspension has just raised the rear of the car by 6inches or so. Could this be the self levelling system gone faulty
Davidp

 

[davidp]

Sorry 124 Estate 1995
DavidP

 

[Richard Elliot]

Hi
not sure if any one can help but my suspension has just raised the rear of the car by 6inches or so. Could this be the self levelling system gone faulty
Davidp

Yes! Sounds like a sensor?

 

[hotrodder]

My first guess would be that the linkage for the SLS height corrector/level controller valve has come off, if you click the first link in post #111 you'll get a pdf explaining how the system works with diagrams of the height corrector valve. If you jack up the back up of the car the valve is ahead of the back axle, trace the route of the rear anti roll bar and you'll find it as the linkage is 'driven' by a bracket bolted to the anti roll bar.

 

[davidp]

Thanks, I will have a look at that tomorrow.

 

[television]

Do check that the link to the valve has not come off 41

 

[Delboy58]

why not put some bags of cement in the boot