Auto-level system flushing procedure??

[intruder]

Anyone know how to flush the hydraulic fluid from the auto-level rear end of a 1998 E320 wagon? Or any similar system?

TIA

Intruder

[loubapache]

I just did my 1987 300TD a few week ago.

I used a feed and flush method and it is not a 100% replacement of the fluid as there is still some in the spheres and rear shocks.

First, only use the MB special hydraulic fluid.

I just attached a small flexible hose to the return like on the top of the reservoir and start the engine. The other end of the attached hose was in a milk jar and you can see the discolored fluid coming out. I waited until the reservoir was almost empty and dumped in a liter of the MB fluid. When I saw the fluid coming out was clear I stopped the engine. It takes about another liter to bring the reservoir level up to the max level. It took a total of 2 liters.

The reservoir itself is disclosed (plastic) so even the fluid inside is clear it may still look dirty from the outside.

I have a 91 300TE 4matic and I have emptied and filled the reservoir several times as a feed and bleed method. I helped another guy at a DIY session with a 123 wagon by jumping up and down on his rear bumper with the engine running while he had the return hose routed to a bucket, but it seemed rather extreme.

someguyfromMaryland

[intruder]

Thanks.

Since you two both have wagons, answer this. How much 'bounce' does your car have if you push down on the tailgate. I get about 2" before it feels like I hit a bumper which I know isn't happening.

I'm wondering if my auto-level is set too light and is engaging too early.

Thanks

Intruder

What you describe sounds about like mine. The rear susp is very stiff and there is no adjustment ever required to my knowledge. Most people screw the system up when they attempt to tune it. The hydro-pneumatic compensator (bellows thingy attached to the rear diff and frame by linkage) is set by the factory to achieve the proper ride height. The dampening characterstics are set by the valving of the struts and the hydraulics.

I've been told by several techs that you only replace struts when you see leakage, pressure spheres are good for 100 - 150 k miles (mine are good at 215 l but the car is pampered), and the h-p compensator as needed for leakage also.

HTH,

someguyfromMaryland

Last winter my 560SEL was bone-jaringly stiff for passengers riding in the back seat. The speheres checked out OK, no leaks, etc. I replaced the rear shocks/bushings and the ride was perfect.

[Redflash]

I changed the reservoirs on a 1980 300TD wagon I had, and if I remember correctly, I jacked the car up, then used another jack to raise each rear wheel to compress the strut. That assured as much fluid as possible was replaced from each strut. A little time consuming, but I think it managed to put more new fluid in the system than would have been possible without doing so.


Ted, How many miles did you have on your 560SEL when you changed the struts?

Redflash,

The 560SEL had about 101k miles. Replaced them with Bilsteins if I remember correctly. Now 107k...