Rear Suspension Problems

[Des]

UPDATE:

Is it a nice day in Sydney to take the 220S out for a drive?


Sorry I'm no help at all

 

[Michel]

Is it a nice day in Sydney to take the 220S out for a drive?

It's nicely overcast, unfortunately I am at work finalising a few things before I go for a week's holidays up to the Gold Coast tomorrow morning.

It would have been a great day for the Ponton...

 

[WGB]

UPDATE:

I have had the 690SEL in the air and opened the nipple at the juction near the rear (passenger side) aircell.
I have let out almost a cup and a half of fluid and then lowered the car and there was NO joy with the pressure still on and the suspension fully extended at the back.

I also started it and moved the disc in all positions without any effect on the back (the front went up and then up again when the disc was turned all the way).

Was the fluid under a lot of pressure?

Did you try lowering the car (or jacking up the wheels with the car raised) with the bleed nipple open and then closing it with the wheels in or near normal position. I think you have a hoist don't you Michel.

You might have to depressurise the central sphere after raising the car by placing it in the M position after disconnecting the control cable to get all the pressure out of the system before releasing the rear pressure.

Sounds like a very stuck ball valve but it should dislodge with the right sequence.

Bill

 

[Michel]

Was the fluid under a lot of pressure?
Did you try lowering the car (or jacking up the wheels with the car raised) with the bleed nipple open and then closing it with the wheels in or near normal position.
Bill

The fluid was under pressure, but I only let off about a cup and a bit and then closed the nipple.
I thought that if I left it open it would discharge the whole container!

I think you have a hoist don't you Michel.
Bill

I do and it makes it very easy

You might have to depressurise the central sphere after raising the car by placing it in the M position after disconnecting the control cable to get all the pressure out of the system before releasing the rear pressure.
Sounds like a very stuck ball valve but it should dislodge with the right sequence.
Bill

I feel that is what i will have to do.
I will tackle it the week after next as I am off to the Gold Coast tomorrow early and still have a lot of paperwork to finalise.

Thanks for your help Bill, I will let you know.

 

[s class]

You may have to let out more fluid. The pressure would have been so high as to almost completely compress the internals of both rear spheres - and there's about a cup of fluid in each.

 

[GreaseMonkey]

Now I know why I am wary of 6.9s, much as I would like one, can I keep up with all this?
Hmmmmmmmmmm.......................
C.M.

 

[Des]

Now I know why I am wary of 6.9s, much as I would like one, can I keep up with all this?
Hmmmmmmmmmm.......................
C.M.

I know if I said what I am going to say on another forum I would be labeled as "6.9 bashing"

But it seems from what I have learnt with these cars from the forums and owning one that it is going to be a continual path of problems and worries unless you spend several thousand dollars to replace everything, struts, spheres, valves, suspension pump etc.. etc.. with all new parts.
That way then you are going to have trouble free motoring for several years.
Otherwise you are going to have intermittent or niggling problems.

Hey maybe there are exceptions to this, but just from what I've seen this seems to be the case.

Don't get me wrong I think the idea, of hydraulic suspension is great, but it has to work, like the Mercedes Benz central locking system, it is clever, rather than using electronic solenoids, it uses gas from the manifold to lock and unlock the doors. I like that, it works, once it is fixed, lines replaced..the little tanks in the doors etc... etc.. it stays working.

I like the ipod, it is a clever and simple to use device, but if it broke every 2 months I would break it for good.


I understand the reality, who can afford to spend $5-10k replacing everything in their suspension with new parts. You could own a Rolls Royce with that sort of maintenance budget.

We live in proper cities with paved roads, not the dirt roads of Africa, I really don't see after driving several Benzes much benefit over a well maintained coil spring car, I'm just not convinced, for all the headaches that can come from keeping something that should stay fixed, fixed.


I am not bashing these cars, I'm really not, I think you just need to be realistic if you want to own one.

 

[s class]

Des, I hear what you are saying. However, having taken the trouble to really understand the suspension system, I now find it is really quite simple, and seldom difficult to remedy. When I replaced all the hydraulics in the blue car, I had a lot of teething trouble getting it all right- but that forced me to understand what was going on. If I had to do it again, I think it would be pretty painless.

I also find that when problems crop up, they are usually pretty easy to diagnose.

Before all this, I too was scared of the apparent complexity of the system.

 

[Michel]

I still stand by my statement that the 6.9 suspension is one of the most comfortable I have ever encountered, possibly THE most comfortable...

And I have tested hundreds and hundreds of cars in my life...

I still find it more comfortbale (in suspension terms) than the RR...

And my SS II is heavenly....

 

[Des]

I still find it more comfortbale (in suspension terms) than the RR...

And my SS II is heavenly....

Really????

That is quite revealing, I really didn't find my 6.9 that great, even after all the work I had done to it,

The Bentley was better, but I found it more boat like to drive.

 

[Michel]

Really????
That is quite revealing, I really didn't find my 6.9 that great, even after all the work I had done to it,
The Bentley was better, but I found it more boat like to drive.

When you go over a rough road or even a speed hump in the 6.9, it is barely noticeable... (especially since I fitted the new spheres)

I feel it more in 'almost' any other car.... even my SSII

 

[Des]

Is it boat like?

where you go up over the wave then down?


Sorry that is the best way I can think to describe it.

Maybe I am a Philistine

 

[Michel]

Is it boat like?
where you go up over the wave then down?
Sorry that is the best way I can think to describe it.

Maybe I am a Philistine

No.... not that wavy.... your suspension must have been seriously worn (I assume you are talking about the Bentley)

 

[Des]

No.... not that wavy.... your suspension must have been seriously worn (I assume you are talking about the Bentley)

No no Bismarck

 

[Michel]

No no Bismarck

OHHHHHHHHHHHHHHHHHHHHHH
REALLY???????

 

[s class]

My two 6.9's are quite different in terms of suspension. Both have new Febi spheres, the blue one has new struts. The red one has original struts. I'm coming to think though that its not only the hydraulics that play a big role. The red car's suspension bushes are better all round, and it shows. The blue one will eventually get rebushed all round.

 

[Michel]

UPDATE:

Managed to spend some time on the 690SEL.

I have had the 690SEL in the air with the disc is the normal position. I opened the nipple at the juction near the rear (passenger side) aircell and let out all the fluid available:
almost one and a half litres of fluid came out (carefully collected in a few clean cups)
I then lowered the car till the tyres touched and ran the engine until it lifted at the front and the back dropped to normal.

I removed the car off the hoist and reversed it out of the garage only to find it had sunk in the back.

I thought that is normal, all the fluid is drained there is nothing to lift it...
So I let the engine run again.... no joy...

I moved the disc in all positions without any effect on the back (the front went up and then down when the disc was turned all the way, but nothing in the back...)

Frustration.....

Yes... I did put the oil back in the tank...

PS: it is 37C here.....

 

[abl567]

Michel, have you checked the rear level valve? Is the arm adrift?

 

[s class]

Did you refil the reservoir before starting the engine? It could be that the pump has sucked air and needs to be primed again.

 

[Bandolero]

Yes, that's what I was about to suggest.
Check and make sure the lever is tight on the shaft and the line on the end of the shaft is in line with the lever.
Mine at the rear was not quite in line and I couldn't get enough height in the rear even with the rod shortened. When I re-adjusted the lever on the shaft it was all fixed.

I love the ride etc on the 6.9. I can go over those humps on the road (that are used in the suburbs to keep our speed down) at 60kph with hardly a bump. These humps are sign-posted at 20kph.