SLS problems.

[Espen W]

Hello everybody!

I have a 1991 S124, that I have been working on for about a year now.
I am experience some weird problems with my SLS system. I have been testing, replacing and wrencing allot. I have also been in contact wit many people. Proffesional MB mechanics, gurus and several of the guys in the MB clubs I am member of here in Norway.

This is a 230 TE (M102) Cam shaft driven pump. Same pump found in W201.

The problem:

- The car rises ~2" above "spring height" in the rear and gets harsh and have an aggressive rebound.
- I can manually operate the lever arm on the valve, and rise the car.
- I can maually operate the lever, and get the car back down, but not all the way down, so it can rest on the springs.
- I have been doing all kind of bleeding, oil replacement etc.
- I have the 124 WIS CD, and have been following all procedures and read all technical information I have managed to dig up.



I have replaced:

- Axle seal and o-ring in the pump.
- SLS valve (tested several new and used valves)
- Small piping from valve to air cells
- Air cells
- Large piping from Air cells to damper hoses
- Damper hoses
- Dampers
- Springs

All original or OE parts. Febi oil, with same number found on the oil tank.

My main therory have allways been the the return lines have reduced flow rate.
I have been using pressurized air, I have used bicycle shifter cables on a cordless drill threw the lines, but there is nothing in there. They are open.
The oil returnes to the tank in rich amounts. If I force the trottle, more oil retures to the tank.

If I open the bleeding niple on the SLS valve, oil comes out, and the car is back down on the springs, but as soon at the engine starts and the system is up and running, the rear end rises and gets harsh.

Everything looks fine, all parts are replaced, but there's something wrong.

I have one observation. Every 20 seconds, I can hear a "clunk" sound in the system. This is a pressure spike. I can feel it, if I hold around the first pressure hose attached to the pump.

Replacacing the seals in the pump was the last thing did, and after that, the spike is harder and I can actually hear it inside the car when I drive.


This is not funny, I am so tired of this. My lovely car is not good on the road.


All kind of answers and/or tips are highly appriciated.




Please note. Car looks ok on this pic, but I have rubbers with one extra knob in the front, and one less in the rear. Just to try to balance, and have some light a litle more than 3 foot in fron of the car.



Espen