Wagons, S & SL have it. Wagon for rear only, others for 4 wheels. My wagon uses PS pump for pressure, a level controller $300 and a gas shock $?, and accumulator $100 for each rear wheel.

Easy to fix, but obviously ($), I want to ID malfunctioning "hissing" part.

Bob

Update on previous post, but still need help identifying "hissing" source and determining if level controller and/or strut/shocks are ng?

* If one accumulator is bad, should I replace the other as well?
Yes, replace both.
* From underside, there appears to be 3 nuts securing the accumulator. Or is there something else securing it?
Just 3 nuts and the hydraulic lines.
* Left side is reasonably accessible, what's the secret to accessing the right side?
Knuckle buster. Maybe disconnecting level controller from its mount.

"Sea foam" appeared while R&Ring fluid, so at least one accumulator is bad.

Rear is supposed to be 1/2" lower in rear. Mine is, but so is left side of car! Ideas?

The door locks work well, but could the "hissing" noise be comming from a vacuum leak?

This all started when I realized on my 94 e320 Wagon, the rear suspension didn't automatically go up or down. And the rear mounted CD player skips a lot more than before. I've never ridden in another Benz, so I don't know how it's supposed to ride/handle. To test it, I had 5 college students in the back. Didn't move.

Suggestions are appreciated.

Bob

The most common self leveling system problem is.....that it works all of the time instead of only working when loaded!

The idea is that the system should compensate when you add weight to the cargo area...when the rear springs start saging..& they all do sag then the system must compensate for that sag..every component has extra stress at the point.

BY re-shimming the rear spring with thicker pads back to the original height will help bu reducing stress on the struts & accumulators..accumulators have to be un-bolted from the inside on a T124 chassis.

Don't know if this helps but hope so...

The leveling system itself should never make any noises.

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Thanks for the reply Doc.

I read cgoodwin's "Hydramatic suspension education" and other posts, so I have a good understanding of the system.

I'll suggest the reshimming to the mechanic. Hopefully, he can level the left to right sides. My wife mentioned that "we" also sag a little to one side at our age. Two days ago, I tried to remove the accumulators myself, but didn't have the strength to undu the 10mm allen for the hydraulic line. Working on my back in my patio/car port repair facility can have its limitations.

On my 94 e320 Wagon, each accumulator has 3 nuts on underside and the accumulator is lifted up and into the cargo area between the second and third seats.

Bob
PS Thanks for all the previous help, especially cleaning the egr and diagnosing & R&Ring the throttle body. Engine running fine, now onto the suspension. I even R&R'ed the tranny fluid. Drain plugs for pan & torque converter! What a great idea! Another one of those little things you get with a Benz.

Mechanic replaced both accumulators. Both definitely ng. No leaking fitings. Another liter to bleed. Now rear doesn't go up or down automatically or manually (as it did before). Moving lever UP of self leveling controller does produce slight "puff" noise. Could system still require additional bleeding?

Is there anything else to check before I have self leveler replaced?

Bob

How can someone tell if their car has self leveling suspension? I think it was an option, not a standard feature, is that right?

1991 300d, 92k

Power Steering pump has additional hose from its lower side to a reservoir. Steel tube from top of reservoir to rear of car connected to a self leveler with lines to two accumulators (steel globe approximately 4" in diameter). Accumulators each feed a strut/shock at each wheel. Standard on all wagons for rear only. Other models have one per wheel.

Bob