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 -??