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Discussion Starter #1
Here's a sort of "how to" replace the rear spring accumulators on W124 estates - this method was worked out by a matter of trial and error - mostly error but may well help other people who are faced with replacing the spheres.

if you are thinking of attacking the job, there are 2 ways to do it, one is the "proper way" which Mercedes book at 5 1/2 hours labour but realistically for the home mechanic will take longer as there are a couple of "special tools" required to do it this way

secondly and in real terms much quicker is to do it the way I ended up doing it and assuming you don't need to grind the old nuts off should take no more than two to three hours actual work.

Parts you will need

2 x suspension spheres - cost about £140 the pair

2 x rubber seals - they sit on the base of the spheres and seal the bodywork - cost pennies

2 x new hydraulic pipes to connect the levelling unit to the spheres - cost about £12 the pair - don't try and make your own there is an insert in them that is designed to slow the flow of fluid

1 x new bracket for the self levelling unit - you may not need this but best to be prepared - cost about £5

4 x 16mm copper compression washers - cost pennies

6 x 10mm nyloc nuts

2 x 1.5 cm m6 (I think) metric fine thread bolts and a tube of loctite

2 litres of MB hydraulic Oil - ZHM fluid - cost about £17

tools required,

axle stands

torque wrench

10mm hex key (preferably socket driven as you need to torque use a specific torque)

11mm socket - to remove the remains of the old unions

11mm spanner - to re tighten the hydraulic unions

10 mm socket with a pretty narrow wall on the socket side to remove the retaining nuts for the spheres

10 mm open ended spanner to detach the self levelling unit

hammer

chisel

cross head screwdriver

optional tool - power drill with mini grinding wheel/attachment or a dremel grinder

rough work plan (isn't hindsight a wonderful thing?)

1, remove the floor section immediatle behind the rear seats - it's held in with 6 cross head screws. lift it from the middle quite firmly - it may seem like it doesn't want to give but it will - it may bend slightly as it's only thin steel but it's easy to straighten

2, with the car up on axle stands attempt to loosen the 6 x 10 mm bolts that hold the spheres in place - don't take all of them right off - you just want to loosen them at this stage to make sure they will move. If they don't or the captive bolt breaks loose - like 3 of mine did you'll need to grind them off from underneath the car once you have detached the hydraulic pipes

3, remove the two bolts that hold the levelling unit in place - the top one is a swine to get at as it is behind hydraulic pipes.

4, place a large bowl under the car and loosen the passenger side banjo union on the base of the sphere (10mm hex key). Let the oil drain into the bowl - you are going to get wet here as you are releasing pressure on the system so do it carefully and when the car is cold - that oil gets bloody hot!!!!!! The "official" method is to attach a pipe to then loosen the screw on top of the self levelling unit to drain the fluid - you'll see why this "alternative" method is easier once you get under the car

5, now repeat that on the other side - do not bend the large pipes out of the way even though it's tempting as it will cause you problems on reassembly (don't ask)

6, when the oil has stopped dripping chisel the unions for the small bore hydraulic pipes off flush with the old spheres and cut them with pliers at the levelling unit, remove the unions from the levelling unit using an 11mm socket and plug the holes to stop any drips - the new spheres you have bought will have plugs in that you can use for this purpose. Pull out the remains of the hydraulic pies and after noting which way they fit throw them away

7, now you can remove the spheres, if the come out easily great - if not be prepared for some awkward grinding of the nuts.

Once they are out, the bracket for the self levelling unit will be freed, so throw that away

If you've got the time to spare I'd take the car off it's jacks/axle stands and leave it overnight at this point with a bowl under the self levelling unit, remove the plugs and let the rest of the oil drip out - it seems to be the most effective way of draining the system completely. Bear in mind that with no pressure at all in the system the car will sit very low on the rear springs whan you remove the jack so don't use a bowl that is too deep

Reassembly is the reverse, put the spheres and the new bracket in and fix them with the 10mm nylocs - torque up to 20 nm

fix the self levelling unit to the new bracket with the small loctited bolts.

connect the shorter of the two new small bore hydraulic pipes to the drivers side sphere and the levelling unit first - you'll see why

then connect the feed to the passenger side.

Connect the banjo unions to the base of the spheres using a copper washer on either side of it and torque up the hex bolts to 30nm - do not try and go any higher!!!!!!!!! and be very careful not to cross thread them - it's far too easy as the spheres are very soft metal - if you do cross thread them you'll need a 16mm metric fine tap to clean the thread (once again don't ask).

With that complete, let the car back down onto the ground and fill the reservoir with oil - you will need about 1 litre initially.

Make sure the screw top is on the reservoir but leave the filler hole open, load the boot - you need a weight of at least 120kg to set it up right so a couple of friends sat in the back is perfect. Get someone to start the car and hold the revs at 2000 for about a minute whilst the suspension rises and add the rest of the hydraulic fluid as required. Once the level of the car and the fluid has stabilised, switch off, unload the car and start it again to check that the levels are fine.

Check for any leaks, take for a test drive and marvel at how smooth the car now feels.....

these spheres have a "life" of about 100,000 miles and if your rear suspension feels harsh or lacks damping they are the most likely source of the problem.

Dispose of the old spheres carefully - before throwing them away you should drill a 3mm hole in the top of them to release any residual pressure/gasses - wear goggles and drill slowly with a lubricated drill bit.

hope that helps somebody


Andy
 

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Accumulated Wisdom....

Andy...You da Man.

WOW.....makes it sound as easy as changing hatch struts.

Only question I have is about bleeding the system. Is there any need to do this and if so.....how. Does this get handled by the assistance of the three (heavy) friends.???

Can't wait to crawl under the car to get a real taste of the hydraulic system.

Thanks, on behalf of all the Wagon Owners.

Ian P.
 

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W124 230TE
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Discussion Starter #3
the system bleeds itself, once you start the car the fluid circulates, that's why you ne...

the system bleeds itself, once you start the car the fluid circulates, that's why you need to leave the screw top on the reservoir as the metal pipe that feeds it is the return.

The heavy friends sat in the back force the system to work, until a certain weight is in the rear there is no self levelling as the car is being supported by it's springs. To ensure the system resets itself properly you need to get it loaded before you restart the car.

Believe me - you will get a "taste" of the system - and that hydraulic oil tastes horrible :)

It's not a particularly hard job, just awkward and once you have decided to replace the few relatively cheap parts (pipes and brackets) the dissasembly time is turned into a matter of minutes not hours.

You can also speed up the full draining of the system by disconnecting the reservoir at the front of the car, for this though you may need to remove the headlamp unit in front of it as the pipe that fixes to the bottom of the reservoir is held in with a couple of heavy duty cable ties which are fixed through the bodywork directly under the headlamp.

Leaving it to drain overnight is by far the easiest option :)

Best of luck, and if your suspension is feeling harsh or bouncy - you'll know when the spheres are gone and you won't believe the difference they make once replaced.

There are also 2 more additional components in the hydraulic system, these being the struts where you would normally have shock absorbers. These are purely for the levelling and to transmit fluid to the accumulators and they either work or they leak - if they are leaking replace them - but be warned they are expensive although you don't have to replace them in pairs though due to them not having any damping characteristics.

Andy
 

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Parts you will need
2 x suspension spheres - cost about £140 the pair
2 x rubber seals - they sit on the base of the spheres and seal the bodywork - cost pennies
2 x new hydraulic pipes to connect the levelling unit to the spheres - cost about £12 the pair - don't try and make your own there is an insert in them that is designed to slow the flow of fluid
1 x new bracket for the self levelling unit - you may not need this but best to be prepared - cost about £5
4 x 16mm copper compression washers - cost pennies
6 x 10mm nyloc nuts
2 x 1.5 cm m6 (I think) metric fine thread bolts and a tube of loctite
2 litres of MB hydraulic Oil - ZHM fluid - cost about £17
Sorry to revive an old post, but I am going to have a go at this myself - thanks to this brilliant set of instructions I think I can do it.

However, although I can easily get the spheres, I don't know where to get the smaller bits - could anyone point me towards a good specialist who sells assorted MB parts, rather than one of the bigger 'generalist' ones like autodoc or mister auto, who only seem to sell the basics?

I am in France, so it doesn't make a lot of difference to me (at least until Brexit!) whether the parts are sourced in the UK, France, Germany or Italy. Germany is probably the best bet, but I haven't managed to find a good seller yet.

Thanks in advance- Alan (W124 newbie!)
 

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Honestly I'm not sure what the fuss was all about. When I did this job a few years ago, the new sheres came packed with the nuts to install them but I don't recall if I had to source the soft washers. That's not a big deal because they can usually be sourced at a local parts store. As for the pipes, unless the OP had rusty pipes, I'm not sure why they had to be replaced.
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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I imagine that rust causes some owners to have nightmares. If that's the case, you could bathe all the removable parts in penetrating oil with a paint brush and leave overnight.

I remember doing this job. The first sphere took a half hr to replace, the second one on the side of the SLS valve took 45 minutes. Hydraulic plumbing in the way on that one.

I don't remember the washers, but if they are copper like in the fuel system you can buy an assortment on Amazon or a decent auto parts place before you take on the job.

Not sure on manufacturer origin these days on the spheres. Febi lists them....gawd knows where those come from. Not sure you can buy them with the Mercedes Star anymore?

Kevin
 

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I don't remember the washers, but if they are copper like in the fuel system you can buy an assortment on Amazon or a decent auto parts place before you take on the job.

Not sure on manufacturer origin these days on the spheres. Febi lists them....gawd knows where those come from. Not sure you can buy them with the Mercedes Star anymore?

Kevin
Kevin, I too don't remember where the washers would have gone. When I did mine, the replacements were Febi. While I haven't had a problem with them from an operational perspective, when I was installing one of them, the mounting stud broke off. Other than having to repair that, the Febi's seem okay.
 

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Thanks guys - very helpful and reassuring. And in fact I have found a really good deal on a kit with spheres, nuts, washers, work gloves and various fluids in a kit. I had a brainwave and remembered that these cars were (and still are, in some places) popular as taxis, and I found this brilliant German taxi parts website selling FeBi (Bilstein) ones for €130!

 

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I have also got to change my headlights, because my car is RHD and the French government make you change them to lights angled for right-hand traffic. Their prices on headlights are also the best I have found, and they are E-marked (another French requirement)

 

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FeBi is just a sub-brand of Bilstein and is a contraction of FE rdinand BI lstein - German likes to take first syllables of words and join them together to make other words - e.g. GeStaPo, StaSi, JaBo (fighter bomber), StuKa (dive bomber), AdiDas (Adolf, or Adi, Dassler, the founder), etc. I have used Bilstein shocks and other parts for years and never had any trouble - they are a German company, although I don't think they are an OEM supplier
 

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I thought that too, but it looks the same on their website - I can't see anything about Krupp (not that that would be a bad name either!). I guess that's why they have to call themselves FeBi Bilstein and not just Bilstein!

 

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Interesting - I live near Turin (I'm just inside the French border, but Turin is just inside the Italian border), and I go past a huge and very derelict ThyssenKrupp factory in Corso Regina Margherita whenever I go there to get car parts. It wasn't derelict when I started going there circa 2002 but has been for a long time, and I always wondered why. Now I know...

 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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Febi is a 'repacker', as they don't make anything. Hence my comment on not knowing where their stuff was originally made.

It was said that the Febi sphere's are OK....just don't expect them to last as long as the OE's did.

On another note.....since MB copied Citroen's live suspension design, their components should swap out with MB. Nobody on this forum has figured out what crosses, that I'm aware of....but could be a potential parts source for us.

Kevin
 

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Thanks Kevin - very interesting. My OE ones only seem to have lasted around 50000 miles - there's a service receipt from way back (1st owner out of 3 before me) for it. This guy:


says that's about par for the course, and he seems very knowledgeable to me - do you have any direct knowledge or experience of him? I'd buy his parts, but he is in Washington state and I am in France, so it's about 8000 miles away...
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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Thanks Kevin - very interesting. My OE ones only seem to have lasted around 50000 miles - there's a service receipt from way back (1st owner out of 3 before me) for it. This guy:


says that's about par for the course, and he seems very knowledgeable to me - do you have any direct knowledge or experience of him? I'd buy his parts, but he is in Washington state and I am in France, so it's about 8000 miles away...
"That guy" sold me a pair of "perfectly good" spheres that supposedly had 5,000 miles on them. They failed almost immediately on my old TE and that sent me down the road to a second replacement/repair.

I like Kent and his videos, but I would be leery of buying used parts from him and in general, any part from him that's not OE. He offers economy parts which is most appealing to cheapskates, but often don't hold up in our cars long term.

Kevin
 

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Does it seem like to you guys they will keep making these spheres? My W126 to replace the sls stuff was so expensive that I opted to do just regular springs and shocks and forget the SLS. But on my W124 wagon I will hold loads in it so I want it to level.
 
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