V220 rear suspension again

[algeir]

My 2000 V220CDI has rear suspension issue once more.
There's no height adjustment going on, but
compressor and solenoids seems ok.
Is there anyone capable of explaining the regulation part of the suspension,
i.e. how the height sensors and solenoids/compressor interact?

 

[Cole@MBS]

Throw the system away and get springs fitted, only way to go!!!

 

[algeir]

Suspension modification

I like the air suspension when it operates correctly, so I'm a bit reluctant to go for springs/shocks.

Last visit to my garage they claimed failure on both the compressor and one air container. Everything pointed in my opinion towards the automatic regulation, and manual testing showed both of the "failures" as bogus.
Doubts about the garage knowledge has made me decide to go for a manual version of the regulation,
making switch operated ground insert to the compressor relay and both air solenoids.
This does not make any changes to the automatic system, but allows for additional manual operation.
I do this without knowing details about the circuits involved, but I see no alternative.

If anyone can tell me how the regulation works in detail, it will be much appreciated. The key information will be how the operation of the compressor relay is generated, and what signal the solenoids get (from the height sensors?).

 

[algeir]

manual control of air suspension

I have used my modification for some time now , and no problems has yet occurred. The only nag is I have to get underneath the car to lower the suspension, and only the left side has got a bleeding point. Afterwards I have to activate both solenoids to cancel the pressure difference. This is easy to work around by installing bleeding points inside for both sides. That will be next step, and a full manual suspension regulation should then be complete.
I'll post some electrical drawing later.

 

[Alex Crow]

isn't there a pressure release valve built in with the compressor assembly?

i think if you actuate this, along with the left and right side locking solenoids you will solve the problem.