One more "Q" steve.
 

I have 95 S500C,I replaced my accumaltors and the upper shock
mounts.Still have right side thump over bumps,not as violent as before bit still very annoying,at what point do you blam the shock?(no leaks!}
Thanks.
Hulio.

I too am having a similar problem with my 92 500SEL. Whenever I hit a bump the passengers in the rear experience lift off. After reading this thread I will look into the acumulator as the culprit. If an accumulator diagnostic thread has been posted in the past, would someone please direct me to this. Also a link to a good online parts store for ordering Mercedes replacement parts would be appreciated.

Thanks,

Jim

Top of the page!
 

I think the firmness of the ride you're describing is the diagnostic... if not convinced, go back a page and read Steve's description again.
As for internet parts, suggest you go to the top of this page and click on Fastlane... they are a sponsor of this site where you get all this neat information for zip.... least we can do is support them.
You'll find that Phil is the best!

There actually is very definite procedures for identifying a deficient accumulator. Unfortunately it requires a good high pressure gauge. It also requires enough labor that if you were paying for it it would be cheaper to buy a new accumulator (but not two)

A good accumulator will have the same pressure nitrogen charge as when new. That pressure is stamped on the sphere and read in bar or atmosperes (same thing sorta).

If the sphere was rated at 1000psi (take bars or atmosheres and multiply by 14.2) then it should have 1000psi pressure inside. Since the gas is captive it can't be directly measured but almost. The way to do it is to install the gauge and start the pump. The pressure will instantly go to the pressure of the gas and then slowly build as the sphere is injected with fluid.

On load leveling systems both spheres and both struts are hooked together so testing this way will only rate the worse sphere. To do the test on each sphere the other must be disconnected and the line plugged.

The question then becomes: at what pressure do you throw them away. Beats me!

Steve,

Thanks for the input and direction, time to put on my coveralls.

Jim

2000psi? Time to put on the kevlar :)

Seriously, is there any residual pressure to expect when the pump isn't running? Do the nitrogen bladders fill the accumulators and flush fluid back to the reservoir?

Sixto
95 S420
87 300SDL

The pressure on the spheres is checked by the level valve. If not the car would drop. If the bleeder is openned at the valve all the fluid pressure is dropped and the nitrogen returns to its natural state (1000psi if thats the spec, less if its defective)

Re: One more "Q" steve.
 

Noises are about impossible without being there. The possibilities include bad parts and all the other components. A loose piston inside the shock is a possibility. Check the subframe mounts also.

Great response
 

Steve you are remarkable with all your answers! MY dealer even says if they don't leak don't replace the struts. On my 92 I noticed the level drop in the reservor, never put much thought into it, they topped it off at a service. Then it got bouncy in the rear, replaced the "spheres", as good as new with 75k miles. "Duh" no leaks where did the fluid go now I know!

Filled them buggers right up.....

steve...
 

i've been on the fence to change out my spheres for about two yrs(i puschased my spheres in 2002-haven't used them yet).i also have the rub noise some are talking about.i traced it down to the bushings and tried and tried to locate someone to redo the bushings but to no avail.now you've given me hope.thanks a ton!
my question is pertaining to the valve near the diff.is it too dangerous to go under the car while runnig and adjust the valve?if im looking at the car from the rear,do i push the valve to the right or left to raise the rear?

I have found that small adjustments can not be immediately seen when adjusting under the car. I can do that on my alignment lift with skid pads (skid pads allow the wheels to move in and out as height changes). Even with skid pads I find that If I make an adjustment that actually moves the car it will be much higher after a ride around the block. The arm is fairly flexible and you should be able to move it one way or the other to see which is up and down. Once you know make a small, matter of fact, adjustment and drive the car. If you went the wrong way go back and adjust it the other way. If you need more or less do it in steps.

looked at that part#
 

steve :went to partslane and looked up your part #.not at all what i thought i would see.i thought we we're talking about the shock rubber bushing that mounts the shock/strut to the subframe?am i confused as to the layout of the assembly or have you posted the wrong #?
i assume the noise was coming from the lower bushing,after thinking about it i guess your saying it is the upper mounting where the noise comes from.correct??is this what your experience has told you?is it ever the lower mount?:confused:

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Accumulators recharging?
 

Is there any interest in recharging the nitrogen in the accumulators?

I do this for accumulators in the Infiniti active suspension system, have the equipment and methods, and own a sl-600, had 2- 560sel's

I would charge what the market will bear, up to 50% of alternative new parts.