Hydromat Suspension Bleeding
 

How do I bleed rear hydromat suspension on 500 sel/123 wagon after installing rear shock absorber accumulators?

You don't have to bleed the system, it apparently self-bleeds. Bounce the rear up and down, or get a couple heavy friends to sit on the rear while the car is running. You will eventually see the rear rise.

AS stated self bleeding....don't drive untill the system raises to the correct position. Bring the RPM's up to 1500 for 5-10 minutes in park.

126 Hydromat Suspension
 

Thank You for the info. When changing old left accumulator some bubbly white liquid came out of it. Old Righ accumulator did not expel anything. With new accumulators suspension dropped about 1 inch but it has raised only about half of that. Pump is good; there are no leaks on the lines or the hydraulic shocks. Car was riding very hard and very bouncy. After new accumulators suspension smoothed out some but it is still hard although not as bouncy as before; there still is a hard knock in the rear suspension going over bumps as well. You cannot bounce the rear shocks by pushing down the rear as you can do in my regular shocks 420 SE. Is it possible that previous owner might have set the rear suspension height lever to the lowest setting when he installed 16" rims andf R rated tires? A Mercedes indy suggested I loosen the top hydraulic hose connection at the shock until liquid expels to let out air? How do I adjust the rear suspension to regain some height? My previous experience with a 6.9 I owned was different; upon changing all 5 accumulators the car rode like a dream.

carlos be EXTREMELY careful if opening hydraulic fittings.these are under high pressure.high enough to drive oil into your skin or eyes.according to MBZ ride height should be adjusted by shimming the rear coil springs not adjusting the level control lever.basic system pressure is also a primary check.this would require hooking a gauge to the level control valve

I am not enough of an expert to contradict the experts here, but in my opinion, when I changed the accumulators in my 124 wagon they did not self bleed fully.

Maybe if you really load up the rear drive around, then unload and so on, it would work, but for me removing the level adjuster and moving the lever myself up and down a few times (lying on the ground engine running) worked well.

I think the adjuster needs to be correctly set, before the system will self bleed. In my case the adjustment was out before I started my job, so when it went back together the system was not cycling properly, hence no bleeding by just driving around.

John

Remove leveler arm from metering valve....raise veh' to max' hight and min' hight three or four times.....valve should get hot.
Check ride hight after 15 mile road trip.

The top shock ram bushes make the bump/thump noise.
Replace the rubber bushes with OE new kit which has been updated .....or use upper shock mounts from non hydro vehicle.



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dkv euro is right, but have it done with the engine running and the car park on a level ground, push all the way up and hold for several seconds before pulling all the way down and stay for several seconds continue this proceedure then it will purge, sometimes it takes forever to purge, but be patient. also try driving with load on the rear it will halp too.

I had presumed the engine running would have been a given...as our good friend COOL pointed out...otherwise the valve would not get hot...indeed, there'd be no fluid flow !

One other point...a 'drive on' four post lift is the easiest way to adjust the suspension, as you could now stand under the vehicle and have access to the leveling valve.

Any other method needs carefull concideration to personal safety being as the engine will be running and the vehicle raising itself fully up and fully down....not a situation where you might want to be.

Drive on floor ramps for the rear will work and the angle will not affect the bleeding proceedure......having done it myself that way.....but as always, safety first.:thumbup:





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Hydromat Suspension Bleeding
 

Followed dvkeuro and cool (Thank You fellows) suggestions to raise/lower the lever while car running and suspension bled all air perfectly. Now I got a smooth running rear suspension instead of a lowrider hard bouncy car. I still get very hard thump more pronounced towards the right side when suspension falls into a pothole or is compressed when the shock goes up; also noticed when reversing on uneven surface that the whole rear end assembly shifted slightly. No uneven tire wear is present. I understand previous owner had car for at least 6 months driving with hard bouncy rocky suspension. Besides shock bushings; is it possible that whole rear suspension assembly is loose or suspension to frame rear craddle (big) busing (No. 123 351 11 42) is bad; or the rear left/right arm bushings (No. 126 350 01 75) that connect to the chassis are bad?