Is this normal SLS behavior?
 

I recently joined the cheap wagon club and purchased a wagon that had a new SLS pump - the PO had let the system run dry so I rebuilt SLS valve, replaced high pressure line and added new Mercedes hydraulic fluid (Febi) Upon start up with weight in the rear, the car's rear end rises up and then drops slowly and repeats this 2 more times and then stabilyzes at the right height compensating for the load and maintains height . . . is this normal for the SLS system? Any thoughts, seems like the car needs a few extra seconds to pressurize -??

No. Air leaving the system would be my guess.

Is there any air in the lines?

How are the accumulators?

system is self bleeding, no leaks and accumulators appear to be original and car does rise . . . .might be time to change out accumulators regardless

How long ago did you reseal the valve? If it hasn't been too long, I'd give it a few times of being loaded down. There may still be air in the system and it needs to be bled out.

How does the car ride?

Car rides good though I notice when I come to a stop car lowers and raises . . hey man, I am an official low rider now! there seems to be a pressure loss somewhere. . . .

The only thing that can cause the rear to raise and lower like that is the SLS valve. The pump supplies the pressure to the valve but it's not going to change the ride height. Are you sure you got it put back together correctly and/or non of the o-rings got damaged while putting them in.

I reworked the SLS Valve O-ring PDF here it is again.
http://oregonstate.edu/~lindgrea/DIY/PDFs/w123_sls_valve_seal_inst.pdf

Can you make it junp up and down at stop lights?:D

I feel very confident that the SLS valve went back together perfectly no damaged o rings etc - I may change accumulators and see what happens as they are quite old and original -

Accumulators generally cause bouncy or harsh ride. They aren't going to cause the rear to lift and lower randomly. When they go bad the big rubber diaphragm inside tears and the whole sphere fills with fluid. Ride height is only affected by the pump and the valve. I still suspect the valve. You might have a valve that isn't working right.

I am going to buy another valve and replace seals as I had problems initially and will replace accumulators anyway as they appear to be original. I was told by an Indie Mercedes shop that they have never had any luck rebuilding SLS valves but scores of people on this site report no such problems . . . probably wanted to sell me a new valve!

Hi
Do you suppose you might have an adjustment problem with the pull rod that connects the SLS Valve lever to the sway bar lever? I don't know this - its just a thought.
Joseph

Thats what I would look for....

Summit in the linkage to the valve from the anti-roll bar....

On my Citroen Xantia (Same basic idea, fully hydopneumatic suspension) the valve is connected by a small plastic link that used to pop off its ball-joints...

The back end of the car would sink or rise depending on where/what position the valve had come adrift from the linkage....
VERY common fault on Xantias....:D

I hadn't thought about the rod from the valve to the sway bar. Definetly check that before buying a new valve.

I've had a couple shops tell me the same thing about rebuilding the valves. A lot of shops don't rebuild parts because it's not worth the money to do it. It's cheaper and easier for a shop to slap in a new part, rather than deal with the headache of rebuilding certain parts.