Rear Suspension Problems

[BenzBoy]

Clearly the suspension can not be fixed. Cut your losses now and I'll write you a check for $500.
I also have a lovely Harbour Tunnel. Interested?
Regards,
Benz-Boy

 

[Michel]

Michel, have you checked the rear level valve? Is the arm adrift?

Not before i dropped it... it was OK

 

[Michel]

Did you refil the reservoir before starting the engine? It could be that the pump has sucked air and needs to be primed again.

I did refill the reservoir.. no air sucking here

 

[Michel]

Yes, that's what I was about to suggest.
Check and make sure the lever is tight on the shaft and the line on the end of the shaft is in line with the lever.
Mine at the rear was not quite in line and I couldn't get enough height in the rear even with the rod shortened. When I re-adjusted the lever on the shaft it was all fixed.

We are talking about the lever near the diff right ?

But..... it was ok before I changed the stupid tyre

 

[Bandolero]

Yes, maybe the lever slipped on the shaft.

 

[Michel]

Yes, maybe the lever slipped on the shaft.

it is suppposed to be perpendicular right?

 

[Bandolero]

The lever should be in line with the slot that is at the end of the shaft.
Also, the lever should be at right angles to the levelling block when the car has adjusted its ride height in the normal position.
This is a borrowed photo of the front control valve and you can see the slot I'm talking about.
Make sure the lever is adjusted correctly and not slipping on the shaft.

http://i103.photobucket.com/albums/m125/Bandolero318/FrontControlValve.jpg

 

[Michel]

The lever should be in line with the slot that is at the end of the shaft.
Also, the lever should be at right angles to the levelling block when the car has adjusted its ride height in the normal position.
This is a borrowed photo of the front control valve and you can see the slot I'm talking about.
Make sure the lever is adjusted correctly and not slipping on the shaft.

http://i103.photobucket.com/albums/m125/Bandolero318/FrontControlValve.jpg

Thanks Bandolero....

I will check it out tomorrow.. IF I CAN GET UNDERNEATH....

 

[WGB]

I did refill the reservoir.. no air sucking here

If the level dropped too low and sucked any air it will not prime until the pressure pipe from the pump to the pressure regulator is disconnected at the pressure regulator end (Car supported, "M" position, diconnect pipe) and the pipe is then pushed into the filler opening in the tank, motor is started and run for a minute or two until fluid flows clean and bubble free and then all reconnected.

I would do this before mucking around too much with your level valve.

Bill

 

[Michel]

Morning Update:

Well this morning I started the 690SEL and drove it around the complex with the ass trailing low (but no scraping).
And then I parked it on a level area and played with the disc.
Low and behold..... it went up in the back, and........... stayed up (fully extended.....

Now it doesnt want to come back down...

 

[Michel]

Clearly the suspension can not be fixed. Cut your losses now and I'll write you a check for $500.
I also have a lovely Harbour Tunnel. Interested?
Regards,
Benz-Boy

Make that $600 in cash, the keys to the M5 Tunnel and you got a deal...

 

[Lukas]

Just think of how many cars you could store in the M5 tunnel.....

Might be a good little drag strip of sorts too.

 

[Michel]

Well, I managed to do the exercise a few times..

Up on the hoist, empty the real cell of the oil and then drop it and let it lift up...

If I leave the lever in the 'normal' position, then the rear is down in the dumps and will not raise.

However, if I turn the disc all the way to the 'raise' position, then it does raise and stay in the maximum position (at the rear) and will not drop back.

Seems like only the rear is jamming while the front wil raise and drop accordingly....

 

[WGB]

Sounds like a problem in the rear levelling valve ?Valve stuck or blocked orifice somewhere.

Bill

 

[B13]

Between my car (misbehaving front) and yours (misbehaving rear) we have one decent 6.9 hydro suspension setup...

Suggest* you change your rear levelling valve with a known good one for testing purposes and work from there.

* I realise the irony of making suggestions on the subject given my constant inability to sort out the problems with my own setup.

I.

 

[WGB]

I think you are nearly there B13 - noithing like persistance even if enthusiasm is waning.

Bill

 

[Michel]

Sounds like a problem in the rear levelling valve ?Valve stuck or blocked orifice somewhere.

Bill

Blocked on the exit side?
Or the valve refuses to 'empty' ?

Hmmm..

 

[WGB]

MIchel - have you got a copy of the M-B document "Hydropneumatic Suspension - Functional Description".

It shows in detail the working of the system and how the channels and ball valves work. It might be better for you to work it out yourself but my feeling is there is a piece of rubber or whatever stuck in one of your ball valves.

If you don't have a copy I can e-mail it to you if you post or PM me an e-mail.

The full document runs to about 8 megs but I have broken it down to four parts which can be e-mailed individually or in pairs.

Bill

 

[Michel]

MIchel - have you got a copy of the M-B document "Hydropneumatic Suspension - Functional Description".

It shows in detail the working of the system and how the channels and ball valves work. It might be better for you to work it out yourself but my feeling is there is a piece of rubber or whatever stuck in one of your ball valves.

If you don't have a copy I can e-mail it to you if you post or PM me an e-mail.

The full document runs to about 8 megs but I have broken it down to four parts which can be e-mailed individually or in pairs.

Bill

PM sent Brother Bill

Many thanks for the thought

 

[-bb-]

Has your mechanic had a look? Might be easier, quicker and much less of a headache... ?