MBenz

Does anyone know the correct level for the hydraulic oil in the container of the S500? I have only 1/3 of the oil in the container and wonder the correct amount of fluid suppose to be in the container. There is no MIN or MAX mark on the side of the container. Thanks for your help.

pcmaher

The cap is supposed to have a dipstick on it. The dipstick has the fill marks on it.

MBenz

You mean the insert filter when we pull the fluid into the container. BTW, do we change the hydraulic fluid and how often? I saw the fluid kind of dirty, it already change its color to dark. Thanks in advance

pcmaher

On my 95 S600, the fill marks are on the attached dip stick on the cap itself. See attached pics. If your fluid looks brown, it's a good idea to flush the system. The color may be an indication that the spring actuators (aka accumulators, nitrogen spheres, etc) are going bad. The rubber diaphragm in these spheres deteriorates after time, and starts turning the fluid dark brown. I would first flush the system, and then keep an eye on it. Check out these threads for more info on flushing...

http://www.mbnz.org/forums/forums/th...184043&posts=8

MBenz

Thanks for your helpful information!

My hydraulic fluid level is below the MIN or the dip was not even touching the fluid. Where was the fluid going or leaking to? I quickly refilled with the OEM fluid to the MAX level now. I didn't even know there is a resovoir until I accidentally open up the tab for cleaning. The owner's manual did not say to check the fluid there.

Do you think the air already got into my hydraulic system yet? How can I find out this? thanks.

pcmaher

You should check all around underneath the car for any signs of oil leakage. Look at all lines, fittings, rear struts, pump, etc. If you see no fluid leaking, the only other place the oil can go is behind the rubber diaphragm inside the accumulators. Look at item #4 in the attached diagram...it is a cross section of the accumulator. The white area is filled with pressurized nitrogen. These diaphragms can leak or rupture over time. Once this happens, the oil level in the reservoir will drop. The ride quality will also start getting worse. Once the accumulator completely fills with oil, the ride will be very harsh. This has to be repaired quickly, as other suspension components will be damaged because of the harder impacts.

MBenz

Thanks for your advice. I'll go under the car this weekend to check out the leaking. If the accumulator fails, how do I replace it? or this must be done by the MB-stealer. I guess it must be very expensive for the job

pcmaher

Instructions are all here...

http://v12uberalles.com/pressure_spheres.htm

MBenz

Happy New Year! Thanks so much for the instruction!

I want to check very careful on the hydraulic system (accumulators) because my car has 53k miles on the speedometer. I have the car for 10 years and seldom drive her due to the parking problem in the city I live.

I would like to change the transmission fluid very soon and wonder what are the parts I should buy for this maintenance job. I am very appreciate your info and knowledge.

pcmaher

Contact Phil at MercedesShop.com. He can set you up with the right filter and gasket. As far as trans fluid, there are many debates on the various forums as to what to use. Some people say it's OK to use Dexron, others don't. My recommendation would be to follow MB's directions and use the MB fluid. The job itself is very simple. Just don't overfill the trans when putting the new fluid in, otherwise you'll see it leaking out.