How do you replace Self-Levelling Suspension on W210

[RANA_1]

Hi,

Can you any one point to instructions on replacing the self-levelling suspension on W210 Estate.

Is this a DIY job ?

regards,

Rana

 

[television]

A few more details would be good, what part do you want to change, and what is the fault on the car

 

[Sean Ng]

I did something about it on a DIY basis as follows:
(1) Replacing hydraulic spheres;
(2) Renewing hydraulic fluids and filter; and
(3) Replacing self-levelling shock absorbers.

Sean

 

[television]

I did something about it on a DIY basis as follows:
(1) Replacing hydraulic spheres;
(2) Renewing hydraulic fluids and filter; and
(3) Replacing self-levelling shock absorbers.

Sean

Stay around then please on this one

 

[Sean Ng]

Some photos can also be provided if required.

Sean

 

[RANA_1]

Thanks for the feedback, I think it is going to be the rear self-levelling shock absorbers.
The info from Sean seems all relevant - can you send more details please.

Rana

 

[television]

I can print you out the instructions as well over the week end

 

[Sean Ng]

RANA 1

Basing on my DIY attempt, I am writing a guide of how to do it.

Will post it once finished.

Sean

 

[Sean Ng]

RANA 1

As an amateur, my approach may be a bit un-orthodox, but I think it works. Please point me out if I did something incorrect.

In general, removing and installing self-levelling shock absorbers are not difficult.

The main features of self-levelling shock absorbers are that they are part of the hydraulic system, and they have a line connecting to hydraulic suspension spheres. The tricky bit of removing them, I would say, is to remove the nuts on the lines. Mine were seized. Use flare nut wrenches with penetrating oil to do the job. In that way, the risk of rounding the nuts is minimised. In addition, prepare for oil spillage (400ml hydraulic fluid was lost when I did mine; total required for the system is about 2L. I did not drain hydraulic system for changing shock absorbers (I did when I changed hydraulic spheres), but do wear protective clothes and have eye protection on.

The 1st photo shows the new and the old absorbers, and the connection points highlighted in red circles. The 2nd photo shows the tricky connection point on the hydraulic lines.

My absorbers were bought from GSF costing about £350. MB dealer would charge a lot more. My car, which is a 1996 W210 E230 estate, was bought 5 years ago with a mileage of 137,000. I did not know when it was last time the previous owners changed them. But I changed mine 2.5 years later at 160,000 miles in April 2007 when they collapsed. Now my car's mileage is 192,000 and they are still in good working order.

The 3rd photo shows clearly about the product code. Hope this will give you a reference when you buy the parts.

In general, the steps are:
(1) Choke front wheels, begin from either rear side, lose rear wheel nuts.
(2) Jack your car up and place it securely on axle stand.
(3) Take the wheel nuts out and remove wheel.
(4) The first thing to remove old absorber is to slacken the nuts on the hydraulic lines. Again, use flare nut wrenches with lots of penetrating oil to do the job. Prepare for oil spillage.
(5) Remove the rest of nuts and bolts of the shock absorbers. For the top nut, the 4th photo indicates where about it is hiding in my estate. I am not sure where about for a saloon. I think boot is a good starting point to check.
(6) If you manage to remove the old absorber, installing new absorber is the reversing order. The 5th photo shows the new absorber installed.
(7) Remove and install shock absorber of the other side.
(8) Once new shock absorbers are installed, refill any hydraulic fluid lost. If you lose 400ml, for example, refill 400ml.
(9) Presuming your car is a saloon, make sure your boot is unloaded (keep spare wheel and basic Mercedes tools in), switch engine on and let the hydraulic system work for a while and stop the engine. Check for any fluid leakage from the absorbers. Not only the rear wheel arches of both side should have an equal clearance (not collapsed), the hydraulic fluid in the reservoir (in engine bay) should then be on the normal unloading level. Measure the rear wheel arch clearance (mine is about 3 inches clear). Check any shortfall of fluid from the maximum level mark of hydraulic fluid reservoir. I would suggest you fill hydraulic fluid in to the maximum level mark. If in case the fluid level is over the maximum level mark, I would suggest you use a straw and remove any excessive fluid. What you do with a straw is: put the straw in, cover and seal the top end with your finger, take the captured fluid out, release your finger and drain the fluid into a container.
(10) Now, load something heavy in your boot and perhaps let somebody sit in rear (when I did mine, I put my 2nd set of 4 wheels in). Turn the engine on and let the hydraulic system work under a loading situation. The hydraulic fluid in the reservoir should then be on a loading level – lower than the maximum level - but the wheel arch clearance should be the same (as measured under procedure (9)). If it is, then the job is done.

Hope the above and the photoo will help. Any question, please ask.

Sean

 

[Sean Ng]

Hi RANA

I did not read you question carefully. Your car is also an estate, not a saloon. So, please ignore what I said about saloon.

Sean

 

[RANA_1]

Sean,

Thanks, this is very useful. One for the DIY Malcolm !
I have to now find the time and the money !

regards,

Rana

 

[Bolide]

Bear in mind that failure of the rear suspension legs is extremely rare and that most faults lie with the spheres, height corrector and pipework

Unless the legs are leaking I would very much doubt they need replacing on a car with that mileage. I would think that the vast majority of W124s, all obviously older than W210s, are still using their original suspension legs

Nick Froome
www.w124.co.uk

 

[R11PAK]

W210 - E320 CDI estate

Hi Sean,

You description and photos are very useful.
I am thinking of changing the shock absorbers on my car, the rear of the car make a thumping noise when going over rough roads, more so then you would except. Have you ever replaced your sub frame mounts, these seem of so i've not changed them?
Did the new rear shock notabily improve the noise, ride comfort ??


thanks

 

[Number_Cruncher]

The only thing I would add is that the hydraulic struts are just that - they are not shock absorbers in the usual sense - they have no damping function at all - they are simply hydraulic rams.

The use of the word shock absorber may be misleading people into changing them when in fact they're OK.

If the hydraulic struts move freely, and do not leak excessively, there is no need to replace them. The damping function, i.e., preventing the suspension bouncing, is provided by the spheres.

 

[Sean Ng]

Hi Sean,

You description and photos are very useful.
I am thinking of changing the shock absorbers on my car, the rear of the car make a thumping noise when going over rough roads, more so then you would except. Have you ever replaced your sub frame mounts, these seem of so i've not changed them?
Did the new rear shock notabily improve the noise, ride comfort ??


thanks

Hi R11PAK,

I changed the spheres 8 months before changing the shock absorbers. I remember that I had the thumping noise before changing the spheres, not before changing the shock absorbers. The thumping noise was gone after changing the spheres.

I changed the shock absorbers because later I saw one rear side collapse. Given the spheres are relatively new and the springs are good, I figured out it would be the shock absorbers that went wrong.

Number_Cruncher's comment is absolutely correct.

Therefore, I would suggest you to try changing the spheres first and see how it goes.

Now the rear suspension issue for my car is that there are creaking noises. I have tried greasing the rear bushes but the problem comes back. My plan is to change the anti-roll bar bushes and the suspension rods. If these new bushes and rods do not help, the next thing I would then consider is to change the sub-frame mount bushes (front and rear). However, before I start, I need a lot more information about how to, since it does not look straight forward on a DIY basis. In case you know how to, please let me know.

Hope this helps
Sean Ng

 

[R11PAK]

w210 spheres...

..Hi Sean,
I've finally got the spheres and plan on fitting them on the weekend.
..how long does this take and what the general procedure to go about getting it done correctly....flushing the system....bleeding the air etc..?

how much fliud did you get..MB gave me 2 litres of power steering liud and said this was enough to refill the system once changed?


Thanks

rupak

 

[Sean Ng]

Hi Rupak

In general, the job is not difficult. When you look at your newly bought spheres, you should be able to figure out what is necessary to remove for replacement.

I have a Mercedes technical note for hydraulic sphere removal and installation in hand. Please let me know your email address so that I can send it (together with some photos) over to you for your reading.

The followings are my approach:
(a) Loose wheel nuts, jack your car up and support it with stands, rather than on ramp. Remove wheels. Wear protective goggles and protective clothes.
NB: Some information suggests to put car on ramp, go under it and release the hydraulic suspension height control lever with engine running. But this will cause the rear to be lower. I skipped this step for not only to avoid the risk of injury, but also to prevent me from breaking the lever and connected pipes as they were so rusty and looked fragile.

(b) Drain hydraulic fluid.
Clip and connect a clear plastic tube securely to the drain plug (similar to brake drain plug) located near the height control lever. Prepare for spillage by placing loads of cardboard paper on the driveway/garage floor. Lead the tube into a container for catching drained fluid. Loose the plug and drain old fluid out with engine running (better to have an assistance to start and stop engine whilst you are monitoring the flow). Once you see some foam coming out, stop the engine and let it drip. Close the drain plug when you see there is no more dripping and the reservoir should then be empty.

(c) Start with one side, slack the nuts connected to old sphere.
Use penetration oil and flare-nut wrench (11mm and 17mm), rather than line wrench that could round off the nuts at the hydraulic pipes. I rounded mine off ending up purchase of new mountings from a dealer. I am sure you do not want to repeat my mistake. Prepare for spillage in this step.

(d) Connect new sphere in.
This sounds easy but care must be exercised to ensure the pipes and the sphere are well connected. The angle of connecting the sphere and pipes, as well as the application of right torque, become crucial. Unfortunately I could not remember the correct torque. Perhaps somebody in this forum can point that out.

(e) Once done, repeat the same process for the other side.

(f) Measure the capacity of the drained fluid which should be about 1.5L to 1.8L.

(g) Replace the hydraulic fluid filter (under the cap of the reservoir) and start pouring new fluid into the reservoir. Pour 1L in first, and tighten the cap up.

(h) With an assistant turning on the engine, monitor the fluid flowing process again by loosening the drain plug until you see new fluid begin coming out (watch the fluid colour). Tighten the drain plug and stop the engine.

(i) Put wheels back on, lower car to floor and tighten wheel nuts.

(j) Top the reservoir with new fluid up to the maximum level. Turn engine on and let the hydraulic system run for a few minutes. Stop engine and top the reservoir up to the maximum level again if you see the fluid level drop. In total, I poured in 1.5L at this stage - at normal loading condition. Check for any spillage. Check and measure the height of the rear suspension (from wheel arch to ground) which should be the same.

(k) Load your car with heavy objects (I used a set of spare wheels plus). Start the engine for a few more minutes. Under this loading condition, with self-levelling suspension running properly, the height of the rear suspension should be as same as that under the normal loading condition. If it is, the job is basically done.

(l) Do a test drive under normal loading condition and check the level of hydraulic fluid level again.

(m) Check for any leakage and the level of hydraulic fluid frequently. Eventually I filled it up a couple of times. Totally I used about 1.8L.


Hope you find the above useful. Any question please ask.

Hope also any expert points out any mistakes I have made or advise for any room of improvement.

Regards
Sean Ng

 

[Solid]

Hi Sean,

Great post, I am just about to try this job myself, can I take you up on your offer to Rupak please.

'Hi Rupak

In general, the job is not difficult. When you look at your newly bought spheres, you should be able to figure out what is necessary to remove for replacement.

I have a Mercedes technical note for hydraulic sphere removal and installation in hand. Please let me know your email address so that I can send it (together with some photos) over to you for your reading.'

I have sent a pm with my email address.

Many thanks

Phil

 

[Bolide]

I think W210 rear suspension is similar to a W124

On a W124, thumping over bumps is caused by worn leading rear subframe bushes. Creaking can be caused by the bush at the foot of the leg. Wandering and self-steering can be caused by worn bushes on the toe control arms. Most other faults are cured by replacing the suspension spheres

Nick Froome
www.w124.co.uk

 

[Pontoneer]

how much fliud did you get..MB gave me 2 litres of power steering liud and said this was enough to refill the system once changed?


Thanks

rupak

I would confirm you have been given the correct fluid before proceeding .

The self levelling systems on all the Mercedes-Benz cars I have worked on specify ZHM mineral oil , the power steering pumps on my cars all run standard automatic transmission fluid . This has applied to these systems on various models up through W114/W116/W123/W124/W126 and W201

It is possible that one system or the other on the W210 series is now different , but please check before risking putting the wrong fluid in .