I see a drop of power steering oil at the most lowest part of the power steering pump. It appears (not 100% certain) to be leaking where the pressure hose in connected to the pump at the bottom. I got my mechanic to replace the gasket ring#6 (see the new diagram link) but it is still leaking.

RealOEM.com * BMW E53 X5 3.0i HYDRO STEERING-OIL PIPES

Since it is a slow leak it is very hard to trace the leak. My mechanic says it is leaking from the pump but I don't see it leaking from the pump

(My mechanic uses the shot gun approach; My power window got stuck and he said the motor had gone. But when I gave a small push it goes up so he says well the "power of the motor is not enough to push the glass as the motor is weak. I told him that I hear a clicking/breaking sound when the glass is going up or down so it has to be the window cable assembly . Then he says then replace both. I asked him only to replace the cable assembly and my window is working fine)

Should I replace the #3 Pressure horse assembly? Any tips to trouble shoot