W124 Wagon Hydropneumatic Suspension - PeachParts Mercedes-Benz Forum

frankstallone · #1 04-20-2008, 04:12 PM

I hope this is the right place to be posting this, I couldn't figure out where else this question might fit on this forum, sorry if I missed something. Okay so I replaced my wheels today and this is what I found when replacing the rear passenger side wheel:

The shock is definitely soaked in what I would assume is hydrolic fluid. Now because the rear shocks are expensive I have to post and ask if it is possible that there is another part like the Accumulator or something else causing this?

I have also heard about replacing the hydrolic system with a regular rear suspension setup but everyone that I have read about says there is nothing like the original hydropneumatic setup.

What should I do?

jcyuhn · #2 04-20-2008, 05:05 PM

There's a 99% percent liklihood it's the shock. If you get under there and eyeball it, there's a chance it's the hydraulic line or a leak where the line enters the shock. In that case I would expect to see hydraulic fluid outside the strut too. But it appears to be coming down the upper part of the bellows boot, so is most likely leaking from the shock itself.

Not much chance it's the accumulator, they are a distance away from the shock.

If the accumulators are good (i.e. replaced in the last 7 years of so, ride not unreasonably hard), I would replace that one shock. If you don't know how old the accumulators are, I would replaced both them and the bad shock. Failed accumulators can cause this kind of damage to the shock.

Lots of folks ask about converting the suspension to a conventional setup, but I don't recall any ever doing it. The self leveling struts normally support a good bit of the weight of the car, so you'd hav to replace the springs in addition to the struts. And a normal pair of shocks (e.g. from a 124 sedan) won't just bolt up to the wagon. I'd guess your least expensive route is to repair what's already in place.

- JimY

mobetta · #3 04-20-2008, 06:36 PM

if those are the same as a 126, i have a pair of good, non leaking units. is there banjo bolt on top? i can get pics, pm or email me.

frankstallone · #4 04-20-2008, 07:57 PM

That is a good question; will the W126 Hydropneumatic suspension work on a W124? I would have to look 2morrow or whenever I really get a free chance to see if the banjo bolt is on top but if memory serves me correctly the banjo bolt is on top.

@Jim - How long of a job is it to replace the accumulator? Special tools required? Fluid involved?

Thanks for reading!

Pete Geither · #5 04-20-2008, 08:32 PM

Replacing accumulators can be a real PITA. Not much room to work and lines need to be disconnected. No special tools needed, just a lot of patience and expertise.

frankstallone · #6 04-20-2008, 08:37 PM

Quote:

Originally Posted by Pete Geither

Replacing accumulators can be a real PITA. Not much room to work and lines need to be disconnected. No special tools needed, just a lot of patience and expertise.

Know anyone with expertise in New Jersey; I don't mind getting dirty if someone with the knowledge doesn't mind passing it on!

Chas H · #7 04-20-2008, 08:52 PM

If the car isn't sitting wrong, I'd say you have a rusty, not bad, spring strut. Hydraulic oil doesn't make a rusty mess. Do you live near the shore? I see some signs of other rust in the background.

babymog · #8 04-20-2008, 09:30 PM

I don't know about the 126, but on the T124 the hydraulic line fitting faces down from the top of the shock.

Quote:

Originally Posted by kaiz3n

That is a good question; will the W126 Hydropneumatic suspension work on a W124? I would have to look 2morrow or whenever I really get a free chance to see if the banjo bolt is on top but if memory serves me correctly the banjo bolt is on top.

@Jim - How long of a job is it to replace the accumulator? Special tools required? Fluid involved?

Thanks for reading!

ds190 · #9 04-20-2008, 10:45 PM

That is not really a “shock”, it is a strut, but gets called that by mistake even on parts lists.

It is clearly leaking, which doesn’t happen that often. Replace it as a single unit, not as a pair as one would do with shock absorbers.

The 126 hydraulic struts are not the same as this 124 strut.

There is no practical way to replace the SLS system with actual shock absorbers like those on the sedans.

This site has a sponsor, from which you can order a replacement strut for $480.

I have been through all of this with my 91 300TE. I had one leaking strut, have replaced both accumulators, and just recently installed a rebuilt tandem P/S SLS pump. SLS is very clever, but I really don’t need it for what I do with my wagon.

Your damage is probably due to the hydraulic fluid having never been changed over the life of your car. Mercedes Benz doesn’t specify anywhere that this fluid needs to be flushed every 30K (just like brake fluid), so basically no one does that. Hydraulic fluid is hydroscopic (absorbs water), and can cause the damage you see on your strut.

It’s a bummer comrade, and not much you can do except replace it..

mobetta · #10 04-21-2008, 09:24 AM

Also- I am sure you can find used parts- I have had reasonably good luck w/ uneedapart.com, they are a nationwide junkyard hotline service. expect to pay 40-60% retail.

seems like my struts wont work.
w124
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w126- what I have-
[IMG]https://www.***************/secure/PartImages/102058.jpg[/IMG]

frankstallone · #11 04-21-2008, 09:55 AM

If I replace just the one strut because they are hyropneumatic I won't hit a bump and one side dive and the other take it like.... a new strut? It seems that if it is a hydrolic system that they would equally work well new or old as the same but I am not sure and want to confirm that.

lkchris · #12 04-21-2008, 12:17 PM

Quote:

Originally Posted by kaiz3n

If I replace just the one strut because they are hyropneumatic I won't hit a bump and one side dive and the other take it like.... a new strut? It seems that if it is a hydrolic system that they would equally work well new or old as the same but I am not sure and want to confirm that.

No, because the struts are NOT shock absorbers, they are load levelers.

Your shock absorbers are the accumulators.

babymog · #13 04-21-2008, 12:33 PM

The shock absorbing is done by the combination of the damper and the accumulator.

The accumulators hold a volume of gas to allow the dampers to push fluid somewhere when compressed, if one leaked and has little/no gas, it will not ride well as the fluid has nowhere to go. This will make the car ride unevenly.

If the damper is bad, it will cause a problem as you see, but as long as it is full of fluid, it should damp equal to a new one (at least close enough to not tell the difference).

I believe there are two dampers, look at the colored paint marks on the damper and ask the dealer which one you need. It is important to match the left/right damper for a proper ride, so if a matching one is not available you will need a pair.

If you find used, buy the pair.

frankstallone · #14 04-21-2008, 10:30 PM

Hmm I wonder if the dealerships around here even have people who are qualified to work on these cars, it seems to me everyone gets educated on the new cars and therefore has no knowledge of the older models. I have a friend who is a mechanic @ a MB dealership and he said he knows nothing about my car.

I wonder how much it would cost to have both accumulators, hydrolic flush, and the one shock done.

frankstallone · #15 04-22-2008, 07:20 PM

Anybody know a reliable mbshop that does a good work in the tri state area? I need to get a quote together to do all this work on the rear suspension and I do not really have the time to learn how to do it.

I am going to call around and get quotes but I am willing to pay for good service and word of mouth is the best thing in my eyes!