560 SEC sls spheres

[GILBY]

Just installed new spheres and the car rides just like before, hard as nails!

Do they have a shelf life or could it be the rams ?

 

[Charles Morgan]

Check the shocks.

 

[GILBY]

No leaks, what else is there to check?

 

[Dieselman]

The shelf life should be long.
Can you bounce either rear corner?

Check the car isn't riding too high or low so it hits the bump stops.

 

[GILBY]

There is bounce, feels a bit stiff though like something's binding.

Regarding ride height, I get 2 fingers underneath each wheel arch and tire.

 

[Dieselman]

If the system has been neglected it might be filthed up to the point the rams stick. Try a flushing agent, or a cup of diesel in the fluid, then new fluid in 1000 or so miles.

as a test to see if the rams are really stuck, with the engine off get a few heavy bodies to sit on the back of the car to make it sink, then start it and check it raises properly.

The spheres really are what controls the ride quality.

 

[bolide]

A good test is to get the car in the air and raise & lower the rear wheels using a transmission jack. If the suspension legs don't extend smoothly, or extend in jerks, they need replacing

I have had this once on a W124. Everything seemed OK but it didn't drive right. On jacking & releasing one wheel the leg extended in jerks. It was bent. A secondhand replacement cured the problem

Nick Froome

 

[GILBY]

I noticed the fluid is kind of black, it was changed about 18 months ago.

What would cause it to turn dark?

Also is there any chance there could be air trapped in the top of the rams?

 

[Dieselman]

Air won't make any difference really as it will add spring.

The fluid is picking up dirt out of the system. Time for a flush then new fluid.

 

[219]

If you can get the car up on a ramp , with the engine running you can operate the lever on the level control valve and see if the car goes up and down .

It is very easy to pop the little link off the valve to do this .

 

[GILBY]

So it's possible dirty fluid could affect the ride?

 

[Dieselman]

If it's really dirty, yes it could make the rams stick.

One advantage of sinking Citroens is that the rams get wiped every time the car rises from rest.

 

[Dieselman]

What brand of spheres did you use?

Is the ride complaint over larger undulations and crashy over sharp bumps, or is it solid feeling all the time?

 

[GILBY]

Is the ride complaint over larger undulations and crashy over sharp bumps, or is it solid feeling all the time?

I used genuine Mercedes.

Ride seems to be like you say compliant over large undulations and harsh over sharp bumps shock bushings maybe?

 

[GILBY]

Also I noticed the leveling valve is hot to the rich after driving it, is that normal

 

[Dieselman]

Not unless they are knocking.

I need to look where the damper is on the Mercedes hydraulic system as that is what causes sharp shock transfer.
As you used genuine Mercedes spheres I wouldn't expect them to have a damper problem, but if they are not the correct ones for your car they might have.

I am changing some on a Citroen due to being aftermarket and the shock damping is wrong.

Flush the system, add fresh fluid, then see.

 

[GILBY]

Hot to the touch

 

[Dieselman]

Also I noticed the leveling valve is hot to the rich after driving it, is that normal

I wouldn't have thought so, it should be cooled by the fluid. Is the pipe from the pump hot?
Could the black fluid be engine oil leaking into the pump? Is the reservoir level rising?

 

[Dieselman]

Hot to the touch

Edit.

 

[GILBY]

Funnily enough I had recently had the reverse problem, suspension fluid leaking into the engine block. Pumps rear seal had gone.

I swapped it out with a rebuilt one, I would assume the sls fluid would be warm/hot due to the pump sitting directly to the engine block ?