Man, I love this SLS on my two cars, and I too concur with everyone here.

I have been restoring a W140 S500 Coupe, and when the tank is dry. The power steering(the pump does two functions:SLS-PowerSteering) pump takes the hit. It destroys the internals.. On this S500 one of the lines was rubbing on the drivers front spring tower.

Add some hydraulic fluid, and start the car up. Watch for leaks. Are your rear shocks leaking at thee bottom? That is one of the places. Next, if this is a East Coast car the salt rusts the lines at a union near where the valve is at. The union on the unibody of the car...

Keep the SLS, I love it on both of my cars..I have hauled about 2000 lbs of rock in my wagon. That SLS levels the car...

Martin