New Accumulators Failed Within 5 Days, W126
 

Very frustrated. I installed two new accumulators (cells), flushed and refilled hyd fluid and installed a new filter. This all took place on 02/04/06. Worked great, the ride was significantly improved. Then on February 8th, the ride was back to pre new cells. It feels as if there is no rear suspension at all. Fluid level is up. Pump is pumping. No leaks that I can detect. I did crack open one of the hyd fittings and it seems as if there is air in the fluid. Harder to detect since the fluid is clean. When I removed the hyd lines from the old cells the old oil just foamed out.

What am I missing? I doubt that I got two bad cells at the same time. And in fact it worked for a few days. We probably only put about a hundred miles on the car after I put the new cells on? I purchased this car in November, first MB. In very good condition, not neglected. I really like the car and got used to a MB ride for a few days. If anyone has any ideas please let me know. Thanks

Double Checked
 

I just looked at the return line again. Oil is flowing in a steady stream.

Sounds like a leak in the low side, letting air in. Air bad.

I had a problem with my hydropnematic suspension on my 300TE wagon after I installed new accumulators. Read post number 23 of thread in link. http://www.peachparts.com/shopforum/tech-help/143256-clanking-noise-rear-300te-whats-source-2.html Maybe the problem you have relates to shocks not being completely full of fluid.

bad hydro cells?
 

Is the ride height normal? If it is, then the new cells HAVE failed. However, your statement 'reservoir is up' points to control valve failure--bypassing high pressure fluid back to the reservoir and not going to the shocks/new cells)--this will normally cause a LOW ride height--riding on the suspension bumpers.

Agree with the control valve issue
 

I think the last two threads are correct in pointing to the control valve. I have been reading the service manual, amazing what you can find, and that points to the control valve also. However the ride height is normal. When I got the car the ride height was low. Changed the cells and did not see a big difference. When my wife got back in town with the car last week the back end seemed to be much higher, even she mentioned that.

So I think, if I am reading right, somehow the rear end is up, the control valve senses that and is sending the oil back to the reservoir and not letting oil get to the cells and struts. Do I have this right?

Thanks for your input.