Hydraulic leveling 560 SEL, rough ride

[lschoelkopf]

Lately the ride appears to seem rougher than usual, like I feel every single bump in the road. Tires rotated and pressure OK.

Can the hydraulic fluid level cause this? It has abou 1/2 " of fluid in the reservoir. What is the correct level?

Where is the best place to buy MB fluids like hydraulic, brake (are they the same), coolant, etc? The dealership?

[mbdoc]

Leveling system getting firm is almost always related to accumulator failure.

[lschoelkopf]

I added about 1 bottle of fluid, and as soon as I started the engine, the car leveled up, and the ride is back to specs! Don't tell anyone how dumb was that? oh wait, I guess I just told everyone didn't I? Anyway, thanks for the good assistance on other issues; this board is great.

[Peter Guenther]

It is an indication of accumulator failure, the fluid is probably in the accumulator and the gas fill in the device has vented. If there are no leaks it went somewhere.

[lschoelkopf]

Originally Posted by Peter Guenther

It is an indication of accumulator failure, the fluid is probably in the accumulator and the gas fill in the device has vented. If there are no leaks it went somewhere.

I see. How can I tell which accumulator, as there are no leaks at all? There are 4 of them right?

[Peter Guenther]

There are only two, the fronts are conventional shocks. Typically as a rule of thumb, the accumulator fails the ride gets a little spongey, and then hard as all the gas disappears. They are usually less than $100 ea, two hours labor plus oil. The struts unless they leak dont fail early, but they have been known to wear the bushings, causing them to rattle. I would watch what happens but replace the accumulators when the ride gets harsh.

[Peter Guenther]

There are only two, the fronts are conventional shocks. Typically as a rule of thumb, as the accumulator fails the ride gets a little spongey, and then hard as all the gas disappears. They are usually less than $100 ea, two hours labor plus oil. The struts unless they leak dont fail early, but they have been known to wear the bushings, causing them to rattle. I would watch what happens, but replace the accumulators when the ride gets harsh.

[lschoelkopf]

Originally Posted by Peter Guenther

There are only two, the fronts are conventional shocks. Typically as a rule of thumb, as the accumulator fails the ride gets a little spongey, and then hard as all the gas disappears. They are usually less than $100 ea, two hours labor plus oil. The struts unless they leak dont fail early, but they have been known to wear the bushings, causing them to rattle. I would watch what happens, but replace the accumulators when the ride gets harsh.

One clarification...when I buy the rear accumulators, the parts house (********az )has 2 different ones:

1. Fibi-Bilstein: Self-Leveling Accumulator Sphere/Air Cell; Front/Rear Left/Right; Nitrogen Chamber with Blue/Green Dot
4 per car. For models with self-leveling/hydraulic suspension.

and this one...

2. Fibi-Bilstein/Corteco: Self-Leveling Accumulator Sphere/Air Cell; Rear Left/Right; For Self-Leveling Suspension System
2 per car.

Both are listed at the correct one for the '91 560 SEL. Any help as to which is the right one to get? THX!!!

[hey_allen]

European cars could have the car ordered with all around hydraulic suspension, but US spec would only have rear.

On the 4 way system, the front pair would be under the left front fender, just in front of the wheel, from the diagrams that I've seen.

That being said, unless you managed to somehow get a gray market 560 (rare), you likely need the second part.


One of the prior threads I read on the subject suggests replacing both if you're going to replace at all. The reasoning given was that the other is likely at the point of failure, and you might as well put them back on an even footing all at once.
(It also removes the problem of poking inside with a probe to find the ruptured one, and dumping hydraulic fluid all over while doing so!)

[lschoelkopf]

Originally Posted by Peter Guenther

There are only two, the fronts are conventional shocks. Typically as a rule of thumb, as the accumulator fails the ride gets a little spongey, and then hard as all the gas disappears. They are usually less than $100 ea, two hours labor plus oil. The struts unless they leak dont fail early, but they have been known to wear the bushings, causing them to rattle. I would watch what happens, but replace the accumulators when the ride gets harsh.

I went to a shop, recommended by some on this board, ready to have the rear accumulators changed, and the indy, pressed down on the back, told me the rear was "spongey" or something similar, and said there was nothing wrong.

Ride still feels hard as a rock, every little bump, everyhere. Find another mechanic?

[pawoSD]

Originally Posted by lschoelkopf

I went to a shop, recommended by some on this board, ready to have the rear accumulators changed, and the indy, pressed down on the back, told me the rear was "spongey" or something similar, and said there was nothing wrong.

Ride still feels hard as a rock, every little bump, everyhere. Find another mechanic?

That sounds like a mechanic who doesn't want to deal with fixing it.....