Check your tranny fluid, it sounds as if it may be low. Otherwise, a fluid and filter change are in order.
The hydrualic fluid for the self-leveling is best bought here on FastLane or from a dealer. while it's not exactly exotic, you don't want to do any damage to the system.
check the rear struts for leaks, also the tubing connections. The fluid has to be going somewhere, and I'd bet the accumlators are rock hard and have beated the struts to death, hence the leaks. Hope for a bad connection or leaking line, the struts are expensive!
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!