Number_Cruncher
Active Member
What's the fault?
- Joined
- Nov 29, 2002
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- 7,663
- Location
- London\Essex
- Car
- E63s s213 2019, E55 2004 Silver-SOLD, E63 w212 Weistec AMG-SOLD, E55 2004-SOLD, C36 1997-SOLD
abt £400 each
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proser
Active Member
Just going through some paper work that came with the car, when I brought it, and in april 2008 when it went in for a service there was a note about the rear shocks being slightly damp; but nothing from the MOT in November 2008. Both were done by the same garage.
the only time I have noticed anything was the rear was sitting lower by about 1" when the caravan (26ft twin axle) was hitched up.
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proser
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Number_Cruncher
Active Member
>>being slightly damp
Oil leakage is one of the only correct reasons to replace the hydropneumatic struts - they aren't shock absorbers or dampers, they're simply hydraulic rams.
I asked my question just to make sure you weren't considering replacing them because the car was bouncing, or the suspension was hard, low, or high.
As the devices look like dampers, they catch people and mechanics out; many are replaced without good reason.
Oil leakage is one of the only correct reasons to replace the hydropneumatic struts - they aren't shock absorbers or dampers, they're simply hydraulic rams.
I asked my question just to make sure you weren't considering replacing them because the car was bouncing, or the suspension was hard, low, or high.
As the devices look like dampers, they catch people and mechanics out; many are replaced without good reason.
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proser
Active Member
They must act as some form of shock absorber ?
Will be getting under there as soon as time allows and will check them out, but then I haven't noticed the fluid level getting lower though.
Just done a bit of a google and found one for sell at about £200 delivered, brand new
Will be getting under there as soon as time allows and will check them out, but then I haven't noticed the fluid level getting lower though.
Just done a bit of a google and found one for sell at about £200 delivered, brand new
They don't at all - they're full of hydraulic fluid, which can't really be compressed. That's why you have the nitrogen-pressurised 'accumulators' in the system, they allow for a damping effect.
Will
where are the 'accumulators'? do they wear out?
my mechanic Steve has told me not to waste money changing the rear dampers ..
I have changed the front ones, and the car does ride better now.
I have changed the front ones, and the car does ride better now.
Number_Cruncher
Active Member
As Will wrote, the devices which look like dampers on vehicles with self levelling suspension are in fact no such thing.
The accumulators, mounted nearer to the centre of the car, and connected to the struts with large bore piping, carry out ALL the damping on the rear suspension, and provide the supplementary springing to support any added load.
The coil springs *nearly* support the unladen car at the correct ride height. There's a small, so-called basic hydraulic pressure which is always present and provides the last little bit of ride height.
Inside the accumulator is a diphragm which contains Nitrogen gas under pressure. When the accumulator fails, the Nitrogen escapes, the springing and damping fuction is lost, and the suspension can become hard and/or bouncy.
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proser
Active Member
Will this also stop the vehicle from self levelling ??
Dieselman
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- Jul 13, 2003
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- 34,199
- Car
- Peugeot 403 Convertible
No. It will just make the suspension very hard.
The ride height can be adjusted using the clamp on the anti roll bar.
The ride height can be adjusted using the clamp on the anti roll bar.
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proser
Active Member
I have disconnect the lever from the bracket on the ARB and worked it, but there is no movement on the suspension.
I have done this by jacking the car up and supported it on axle stands under the rear springs to make sure the hydro's are at their normal height
how do I know if it's the valve or the hydro's ??
I have done this by jacking the car up and supported it on axle stands under the rear springs to make sure the hydro's are at their normal height
how do I know if it's the valve or the hydro's ??
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proser
Active Member
I have adjusted the lever to make it sit lower but no movement, after putting it back on the ground. There is some bounce in the suspension so I assume that the accumulators are okay.
There was a light coating of oil ( Along with stuck on dirt) on the hydros a few weeks ago before I cleaned them and they are still dry now.
What I am trying to acheive is to drop the suspension to avangarde height with mb spec springs
So may be thinking that it's the height valve that has gone bad, thoughts from the more experienced ?
Just had a call from dealer and the height valve is £258 + vat !
There was a light coating of oil ( Along with stuck on dirt) on the hydros a few weeks ago before I cleaned them and they are still dry now.
What I am trying to acheive is to drop the suspension to avangarde height with mb spec springs
So may be thinking that it's the height valve that has gone bad, thoughts from the more experienced ?
Just had a call from dealer and the height valve is £258 + vat !
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The 'usual' fault on these cars is for the hydraulic pipes underneath to rust and cause loss of fluid - check the reservoir under the bonnet - if it's empty there's your problem .
Otherwise the level control valves do sometimes go faulty , as do the pumps , and diaphragms are known to fail in the spheres , but that manifests itself as a very hard ride along with low fluid level .
I've had three estate cars with SLS and had to replace the pipes on each one .
PS - valves , pumps etc can be had for reasonable money from a breaker - something of a gamble as you won't know if its good until you fit , but can save a lot of cash . A decent breaker will refund or exchange a dud unit .
Otherwise the level control valves do sometimes go faulty , as do the pumps , and diaphragms are known to fail in the spheres , but that manifests itself as a very hard ride along with low fluid level .
I've had three estate cars with SLS and had to replace the pipes on each one .
PS - valves , pumps etc can be had for reasonable money from a breaker - something of a gamble as you won't know if its good until you fit , but can save a lot of cash . A decent breaker will refund or exchange a dud unit .
Dieselman
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- Jul 13, 2003
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- 34,199
- Car
- Peugeot 403 Convertible
Rather than actually faulty the valve could well be stuck up with debris as the MB hydraulic system isn't a recirculating one and nobody changes the oil.
Try holding it in the raise position for several seconds with the engine running and see if that works, alternatively disconnect the output to the rams pipe and operate it then, it should gush fluid out.
It's worth stripping and cleaning the valve if it won't work.
If you can get it to deliver some fluid change the oil but add half a cup full of diesel/paraffin/turps to flush the system out. Run like that for a few weeks using the self leveling as much as possible then change the oil again.
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proser
Active Member
Reservoir is good - no loss of fluid, but did notice that the pipe, from the valve, to the T piece was rather rusty so will get that replaced.
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