W108 Hydropneumatic compensator OK?

[TroutMD]

Hi, I am new to the forum.

I recently bought a 280se 4.5. The car has been stored for a loooong time (30,000 orig miles). When I bought the car, it was very low in the rear so I figured I needed to replace the hydropneumatic compensator with a spring kit like many of you have.

However, after driving it 200+ miles, the car appeared to have "leveled itself" back to what looks to me as being close to normal?? Has anyone else experienced this?

I have attached a few photos of the car as it looks now, see below. I did not take a "before" photo but it was significantly lower in the rear. I have read the rear should be 1" higher than front, but the rear still looks more even or maybe a bit lower than the front so I may still need the replacement done?

Thanks in advance for any insights. Please note that I am not very mechanically inclined.

[ScooterABC]

Take a picture from the back at ground level. Are the wheels vertical, or pointing towards each other at the top?

[TroutMD]

Originally Posted by ScooterABC

Take a picture from the back at ground level. Are the wheels vertical, or pointing towards each other at the top?

See below for a few photos from back. They appear to fairly vertical? Thanks again for your help with this.

[Idle]

This looks and sounds normal. I have fooled with these several times.

These are nothing but a big shock absorber. A shock absorber under very high pressure to be sure, but a shock absorber none the less. After they sit for a year or so they tend to 'level out' pressure wise and you get what looks like a worn out compensator.

But you can bring them back to life by removing them, pushing down on the shaft (which takes a lot of pushing) and letting them expand back out. Or you can just put up with driving them for a few hundred miles and they will either do it themselves or they will not. If they don't then they are shot.

These can be rebuilt but it is expensive and the only place I know of that is still rebuilding them is in Germany. You can also still buy then new but the cost is really high for that option.

These often show up on Ebay in working condition.

But from the way you describe the ride and the position of the tires I would say this one has pumped up and you don't have any problems.

[TroutMD]

Thanks so much, that was very helpful indeed. This forum is great, I am sure I will have plenty more questions in coming years

[berfinroy]

The Nivomat compensator is not a "mere" shock absorber: it has the unique ability to automatically adjust itself through internal mechanical valving action to maintain constant ride height regardless of load. See attached website.
In modern cars this kind of thing is now done with electronics.

Cars | NivomatŪ - ZF Friedrichshafen AG

[Idle]

Originally Posted by berfinroy

The Nivomat compensator is not a "mere" shock absorber: it has the unique ability to automatically adjust itself through internal mechanical valving action to maintain constant ride height regardless of load. See attached website.
In modern cars this kind of thing is now done with electronics.

Cars | NivomatŪ - ZF Friedrichshafen AG

Very true. But the original question was: Is this normal?

When explaining a very technical subject it is easy to slip into an area where the reader is totally lost. So keeping it in simple terms is always best.

When someone asks me the time I don't tell them how to build a clock, but the information link you posted should be read by anyone who wants to truly understand how these things work.

If noting else a reading of the linked information will let most people know they cannot rebuild these in their driveway.