85 300TDT Self Leveling rear, question
 

Does anyone know the process for diagnosing the self leveling system to my MB wagon. Took a load of cobblestones the other day and I think I may have done it it. Some weird noises came from the R side rear. Checked the fluid today and noticed it to be very low. Will add more tomorrow. It rides very low right now, and the leveling system does not rise with a load any longer..

There is some great info posted about that...

Here are 75 threads found with the seach feature... if they don't have what you need ask again... you will be able to ask more specific questions about what you don't understand....

http://www.peachparts.com/shopforum/search.php?action=showresults&searchid=454937&sortby=lastpost&sortorder=descending

Self leveling
 

The system works by using fluid from a engine monted pump and controlled by a valve in the rear connected to the torsion bar. The shocks each have hoses that go to spheres that have a diaphram one side of which is filled with nitrogen, possibly one diaphram let loose. It is not a hard job only messy, since it is under pressure.

How do you determine if you have a bad diaphram? Is there a way to test them??

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...ok,

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THe 123 chassis manual devotes 84 pages to the self leveling suspension...

If you read and follow that advise in those threads from the search.... You are likely to find that some MUCH SIMPLER and EASIER to fix item in your suspension is at fault...like a stuck or broken level control arm...

If the event that is not the case.... it is possible that just buying new nitrogen pressure cylinders would be easier than actually testing them.

If not, then you may need to acquire a 123 chassis manual for repairing them. It is not always feasible , or safe, for some items, to rely only on what is available on a forum....

These items are under pressure, with possibility of oil mixed into whatever might be sprayed into your eyes..... wear appropriate eye protection when dealing with it.

I appear to have a leak somewhere, however I've yet to get it to a lift. It has been raining 3 days here in NY so lying on the ground is out. Could a blown air cell/accumulator be the cause of leaking? Where should I look first. Someone said its easier just to replace the air cells. I can't say if they've ever been replaced. I comming up to 373k so I guess they may have worn out.:confused:

You are going to have to get up underneath it to find a leak. It should be visible once you get up under there looking around with a bright light. Repair/replace the leaking part and refill as required.

I crawled under the car and didn't see any signs of leaks. I do remember seeing light oil on my fan belts. I assumed it was from My AC compressor, now I not so sure. Is there anyway of telling whether the hydraulic pump is gone??

With your engine cold... make sure of that... cover what needs to be covered with plastic bags or what ever... then really clean your engine and the compartment...I use concentrate gunk mixed to proper proportions with kerosene.. DO NOT USE gasoline...
spray the mix on the engine and let it sit overnight... then spray again and let it sit a while... then spray it off .... if your engine has been neglected in the " cleaning " department... you may have to do this several times.... no need to spray the mix on a wet engine.. only works on dry ones...
Then go drive it a little ways.. and keep checking closely under the hood and ( if you clean the rear suspension ) check at the rear for oil seepage...

Unless you want to pay someone to look for it ... YOU are Going to have to get a little dirty to find your problem.... and into the engine compartment and under the rear suspension...

thanks for the tips, I'll give it a try

I just take my engine compartment on a little visit to the car wash and its high pressure hose. Washed the 409d last week and found the oil leak at the filter housing in less than 5 minutes.
If my memory serves me correctly, there was a thread within the last few months where someone else had a leak in the hydraulic system at the front of the engine.

Shear2001, Just be sure your car engine is cold.... if you put water on the fuel injection pump with it hot... you can mess it up really badly....