S210 spheres?

[welland99]

Wrong one, that's for your Xenon headlights.

The SLS valve and linkage is on the same side (off side), right above the diff.
Hardly possible to be more inaccessible.

OK, thanks - I forgot about the headlamp levelling system.

 

[millo777]

Its worth checking the condition of the sls hydraulic fluid. When the spheres fail, the fluid becomes very dark form the contamination from the ruptured gasket within the sphere.

On the w124 and w140 there is a filter on the return pipe into the fluid reservoir. Check that for evidence of the spheres failing.

 

[welland99]

I've now found the SLS valve: it sure is in an inaccessible spot!
Anyway, I've disconnected it and moved it to the top position, then started the engine. The car quickly lifted up evenly on both sides. When I stopped the engine, the car stayed up until I moved the lever the other way, then the car came down again.

So, struts, pump, pipes, fluid are all OK.

But, I'm now confused about how the spheres could be shot. Could it not be that the SLS is calibrated to the wrong height?

The linkage is in two pieces, and one of them is in two parts which slide. If I adjust this longer, it will raise up the rear. Is there any reason why I should not do this?

 

[renault12ts]

I thought your problem was a "thump" from the rear suspension, not ride height?

 

[welland99]

I thought your problem was a "thump" from the rear suspension, not ride height?

Originally, it was a thump, then it became a very hard ride with little suspension travel at the rear.

I did not think that the rear ride height seemed wrong, but I don't know what the correct height should be. So maybe it is incorrect. In fact, thinking about it, I have not noticed the Self levelling system jack the car up for quite a long time.

Now that I have shown that the level can go up and down under the hydraulic power (when the actuator valve is operated manually), I am beginning to wonder if the problem is down to ride height after all.

Maybe the thump and limited travel are caused by the suspension hitting the limit stops? Or, do the hydraulic struts lock up under some circumstances?

 

[renault12ts]

My rear height is 365mm from wheel centre to top of the arch.

 

[Charles Morgan]

The spheres serve two separate functions - as suspension damper and as hydraulic accumulators. In the former, the sphere works with oil under pressure being pushed against a membrane with pressurised nitrogen behind that. Over time the membrane becomes pervious and the gas escapes, so there is nothing to exert pressure against the oil, so the suspension bangs. As an accumulator though, the sphere will continue to hold pressurised oil, but will need a bit more of it to fill it - so the pump works a bit harder. So you continue to have self levelling but without the damping effect of the nitrogen.

I am quite sure if Dieselman was around he'd correct me on all the above but I wouldn't get too hung up on the SLS being wrongly set up as the cause. Change the spheres and then see.

 

[welland99]

My rear height is 365mm from wheel centre to top of the arch.

Thanks. Is that with the engine running, after the SLS has adjusted itself?

 

[renault12ts]

Thanks. Is that with the engine running, after the SLS has adjusted itself?

That was engine off...and I have an Avantgarde.

 

[welland99]

That was engine off...and I have an Avantgarde.

Is that the best way to measure it? Would it be more correct to do it with engine running? Mine is an elegance.

 

[renault12ts]

Is that the best way to measure it? Would it be more correct to do it with engine running? Mine is an elegance.

Just tried with engine on...made no difference.

 

[welland99]

Just measured my ride height. Taking measurements from the wheel centre to the lower edge of the highest point of the wheel arch, my range is 380 to 440 mm. When I reconnect the SLS linkage, it settles at 380, ie at the bottom point.

Does it sound correct that it would settle at the bottom?

As an experiment, I've disconnected the linkage and set the height at 410mm (ie the middle point). I'll go for a spin shortly and see how it feels.

 

[welland99]

As an experiment, I've disconnected the linkage and set the height at 410mm (ie the middle point). I'll go for a spin shortly and see how it feels.

Well, I think it is a lot better now. I went for a drive on the bumpiest road I know near me and I didn't detect a thumping noise and the ride felt much more supple.
I think I'll adjust the adjustable linkage to set the height at 410 mm and try it properly for a while.

I'd still be interested to hear the rear height of other elegance S210s. Is this something specified in a service manual? I rang my local MB dealer today to ask and was told they'd have a look and get right back to me. I got no reply.

 

[welland99]

I have a reply from MB about the ride height. They don't set it up with reference to actual height, but with reference to ride angle. They attach a magnetic inclinometer to the chassis and the angle is 1.9 degrees +/- 1 degree.

That doesn't help much without an inclinometer, does it?

 

[hotrodder]

Just sticking a inclinometer/angle finder to the floor doesn't sound right to me? Based on 123s & 124s rather than 210s but typically setting the neutral point of the SLS system involves a full tank of fuel and some weight in the back (officially specific tools are used to load the rear suspension instead of sitting a hefty mate in the boot). Static ride heights are set by the coil springs and different thickness of spring pad

ETA if i'm wrong then cheapnese magnetic angle finders can bought very cheaply. If they're anything like cheapnese digital vernier calipers they're probably just as accurate as decent ones just nasty/fragile if you rely on them on a daily basis

 

[tjamesbo]

I set mine up so that it looked level when it was loaded I didnt want it sitting down at the rear so I loaded it up 2 dustbins full of water

Then played with the arm ,I measured the height of the rear arch compared to the front and also visually checked how level it looked My guess is that as i wanted it level and not sitting down IIRC I ended up with the rear slightly higher than the front and it looked right cant remember if it was 5mm or 10mm but that cant be far of the incline spec

 

[welland99]

Update:
Not used it much in the last 2 weeks. Although it did seem initially better at the higher ride height, it is definitely still very hard at the rear. (Probably just as hard, to be honest).

Is there any reason to avoid changing the spheres (ie any other checks I should do first?)

 

[welland99]

Procedure for changing 210 spheres

Planning on a DIY attempt to change my spheres in the near future. Can anybody offer any advice from their experience?

What size / type of tube should I connect to the bleed nipple? And where could I get it from?

 

[hotrodder]

Can't remember if the bleed nipple on the SLS valve is larger than for brakes. Any hose that fits* will make life less messy but that nipple is more about relieving system pressure than for actually bleeding it after changing the spheres... it will self bleed eventually, more quickly if the SLS is activated by manually moving the valve etc
Giving the unions you'll need to disturb a good dousing with plus gas would be a good idea, can measure the bleed nipple while you're under there. If you don't already own a set of flare nut spanners (6 point style/single hex rather than 12 point/bi-hex ideally) i'd have a measure up of the unions too and buy the size(s) needed as they're far less likely to round off unions than a regular open ended spanner


* car accesory shops/motor factors, decent ones at least, will stock a variety of sizes along with the bay of evil (clear pvc tube used for fish ponds/aquariums/brake bleeding etc)

 

[a111r]

Don't bother using the inaccessible bleed valve.

When the first 11 mm sphere union eventually comes off, just use that to modulate the release of fluid until the 'foaming Guinness' subsides.