Mercedes hydraulic suspension advise please!

[D Spares & Tyres]

Anybody out there have any experience of this?

 

Mine is a 1980 W123 240TD

 

hydraulic self levelling suspension on rear, with a fluid pump and Citroen style spheres. It usess LHM too

 

Car has been stood 13 years or so, and in getting it back on road, it seems most of the pipes are rotten, its leaking fluid. One wass broken, I have fixed it but others are leaking

 

Not sure if I ought to replace all the pipes and hope the rest is Ok ( may have rust and dirt in system ) or shall I just junk it and fit standard struts off a base model? I assume this would be straighforward?

[Lacquer Peel]

Is the suspension lifted wholesale from Citroen, pipes, unions and all? You can buy sections of Citroen hydraulic pipe quite cheaply.

[bigfella2]

What a cool motor. If it were mine I would bin it off and go for regular suspension. Any pics?

[Junkman]

You should replace all the hydraulic pipes and then flush the system.

Please invest in a manual and work according to what is outlined in there.

 

Converting it to the saloon suspension system is not only detrimental for using the car properly, but also more expensive than rebuilding it.

 

Do this properly. Don't fuck it up.

[spike60]

Unless they've already been done which is likely the brake and fuel lines will be shagged as well, think they follow the same run front to back.

[skattrd]

Do this properly. Don't fuck it up.

 

You have been told!

[twosmoke300]

You have been told!

 

Must

Resist

Charade

Comment

😄

[forddeliveryboy]

I think the pipes from the spheres to the struts have damping sections within them, so use the genuine Mercedes parts - they're not expensive. Converting is much more effort than you'd imagine, and the results are poor.

 

The hydraulic back axle is superb when working correctly and the spheres last more than a decade/150,000 miles, it's well worth sorting. It makes the cars really special as well as more capable.

 

The struts are mega-pricey new, but only leak if old knackered oil and flat spheres are used with a hard-worked car. Having said that, I once picked up a s/h one for £40. Use the correct oil - not LHM - and set the ride height spot on - this is v important otherwise the hydraulic bits are strained. Mercedes says the system self-bleeds - it doesn't, you have to crack the union near to the strut as there's no supply and return to it.

[Bear]

What everyone else said. Make sure and use the right oil, too. Secondhand struts should be fine if not actively pissing oil.

[D Spares & Tyres]

Thanks for comments

 

Still undecided. Self levelling was a cost option on these so most had normal suspension I think

 

As I won`t be carrying heavy loads it seems like a pointless complication and expense to me as part of the attraction of an old Merc is its simplicity and reliability.

 

But these things are rapidly rising in value and maybe it would devalue it slightly?

 

I`ll go down the yard now and have a play and take some pics and have a think about it

[Bear]

Devaluing a 123 right now is daft. Ditto 124s. They're not hard to DIY, most of the cost came from labour rates and specialists misdiagnosing faulty struts instead of just needing spheres. Unlike Citroën owners, a lot of Mercedes owners had absolutely no clue what lurked beneath the car.

[forddeliveryboy]

Would you fit cable brakes to your car if the hydraulic lines rotted?

 

There's so much mis-placed hysteria over suspension with centralised hydraulics instead of four separate hydraulic dampers and four awkward to change steel springs whether on Mercs or Citroens - yet at worst on a 123/124 it's usually a couple of spheres (ok, so not a 5 minute job like on a Cit but similar times to replacing steel springs and separate dampers), freeing up of the valve and a fluid change. The pumps which sit on the front of the engine are a doddle to refurb if they pump less well at lower revs - I've only ever known one grow a bit feeble at tickover revs.

[D Spares & Tyres]

If it were the case that the standard models had cable brakes and worked fine then yes I would consider it,

 

and if my aunt had a cock then she would be my uncle, but thats not the issue here either.....

 

My point was that most of the pipes are rotten and they may well be dirt and rust fucking the whole system especially as one of the unions has been open for a few years so I just thought it would be far less of a headache to put it to the standard that most Merc 123s are in rather than replacing the whole system piece by piece at great expense when all I want to do it drive the fecking thing.......... 

[beko1987]

Replace pipes and spheres. full fluid flush!

 

Then drive for 3 months like a BOSS then fluid flush again, and whatever the merc equivilant of citrobatics are frequently!

[forddeliveryboy]

Fairy nuff. Just report back on how straightforwards a job it is and how the car goes afterwards. I didn't know the fluid suspension was a cost option on the wagons, only the coupes. The saloons all had steel springs, unless a factory limo conversion afaik.

[Andrew353w]

You should replace all the hydraulic pipes and then flush the system.

Please invest in a manual and work according to what is outlined in there.

 

Converting it to the saloon suspension system is not only detrimental for using the car properly, but also more expensive than rebuilding it.

 

Do this properly. Don't fuck it up.

As he says, the system is basically a Citroën one, with Mercredi bits. Drain, check all unions, seals and pipes for condition and leaks; replace/repair as necessary. Replace fluid, drive about a bit, check level, drive about a bit more, repeat checks for leaks &c., change fluid and enjoy the best ride ever!

 

Just for once, R.T.F.M. (read the f88king manual) DOES apply-it'll be well worth it! If your S.E. England based I know 2 firms, one in Cambridge & one in Watford who I can personally recommend to help, if needed.

[Bear]

It's not quite like Citroën, in that the car has coils as well.

 

https://mercedessource.com/problems/suspension/diagnosing-and-repairing-hydraulic-self-leveling-suspension-sls

 

If I had a W123 wagon, aside from "not being at the computer but instead being outside admiring it", I'd do the rebuild. I've had a W124 where the system leaked and got repaired properly, and it was amazing - and I've driven two where it's clearly fucked. Oddly enough, my W210 is also in need of new accumulators and a flush through - and it'll get them.

[michael1703]

I think the pipes from the spheres to the struts have damping sections within themi

I cut one open and found that merc had just put what looked like a stainless welding rod inside them

 

So I used standard 3/16th brake pipe with a bit of oxy acetylene rod inside them and it worked fine

[D Spares & Tyres]

Thanks people. I`m not scared of hydraulics, I really like Citroens too. Of all my Citroens, the suspension had never been an issue

 

well today I bypassed the rear suspension so as not to ruin the pump and have actually driven it for the first time in a year of ownership!

 

its only temporary don`t worry, but it drives ok even if it is a little low on the rear...

 

Pretty sure after all the comments and helpful advise I shall keep it hydraulic but here have some pics as requested...

[D Spares & Tyres]

Lowest mileage 240d?

[dollywobbler]

Simply slam the front suspension to match. Sorted. 

[Lacquer Peel]

The self levelling suspension will be ideal for carrying large quantities of veg oil.

 

Is the Mercedes hydropneumatic setup licensed by Citroën or is it their own take on it? Unsurprisingly Mercedes enthusiast websites don't mention any French influence.

[dollywobbler]

I have a feeling they copied it but changed enough stuff to get out of a licence fee. But I think Rolls Royce paid a licence fee, but then made a load of changes anyway (also using springs and spheres). I may not have got that entirely right though.

[Bear]

Lowest mileage 240d?

 

Been around the clock. Just run in. Probably.

 

It looks horrid. Total liability. It should be given to me to be, er, disposed of.

 

*hides the T-cut and Inchcape parts dept. speed dial*.

[forddeliveryboy]

Mercedes took out a licence from Citroën, then did their best to disguise the fact that it was anything other than being something like a bit of bog-std tech. To be seen to be like a mad French company mullers resale value and puts off people who like being feather-bedded with feeling like they're one of the crowd.

 

Because the spheres are so awkward to access, they made them last longer than the froggy ones. The rest of the system is a bit cack-handed to work on, but since there is the presence of a coil springs near the rear wheels, mechanics don't deliberately fuck them up. I've seen more than one three-starred bill for replacing the struts nearing £2k, when nothing was wrong with them - but the wooden ride and knackered spheres are left well alone. There was a 124 estate on ebay a few years ago and the ad stated thousands had been spent on the car suspension and the garage couldn't work out why the ride was still poor.

[Bear]

It's funny how much crossover between Mercedes and Citroën owners exists. Ignoring the 21st century crap (including the C6), I'm about equally passionate about Mercedes and oleopneumatic Citroëns, with I think 22 of the latter buggers, mostly CXs. in my past. When I got the E320 the owner lit up talking about his past Citroëns. And if you've had a HP froggy, you recognise the feel of a knackered sphere even if there's a coil spring lifting the car up.

 

Never mind Renault, imagine if Mercedes had paired with Citroën...

[forddeliveryboy]

...or Citroën with Honda. Not that in the early seventies that would have been readily possible.

[D Spares & Tyres]

Simply slam the front suspension to match. Sorted. 

I did see a slammed saloon on the road not long ago and it did look really cool apart from the people inside were jiggling over the bumps as there was no suspension travel left on the poor car. Seemed bit daft really. I`m not into modified stuff, although the merc does need a bit more power. I shall leave it standard though

 

I wonder how many people bought a 240TD thinking it was a turbo diesel.... If mine is a turbo then I think it may have been put on backwards judging by the power output....

[D Spares & Tyres]

It's funny how much crossover between Mercedes and Citroën owners exists. Ignoring the 21st century crap (including the C6), I'm about equally passionate about Mercedes and oleopneumatic Citroëns, with I think 22 of the latter buggers, mostly CXs. in my past. When I got the E320 the owner lit up talking about his past Citroëns. And if you've had a HP froggy, you recognise the feel of a knackered sphere even if there's a coil spring lifting the car up.

 

Never mind Renault, imagine if Mercedes had paired with Citroën...

The only way that would improve my Merc is if it had French seats. I`ll never understand why Mercedes have to fit such horrible seats to their `luxury` cars. Anything French is more comfy

[Bear]

It's a weird thing though - CX seats look and feel - initially - supremely comfortable. Yet a 400 mile drive and my back was killing me. My old 200TE's MB-Tex seats had all the give and appeal of a plastic school chair, but after 400 miles, no pain. Now, the W210 seats, the non-ortho type, are really quite poor. No lumbar adjustment on a car with electric seats!