Power steering unit has a leak on the upper section of the pump. I have tightened the bolts on the rear of the unit and had the rubber hose to the radiator replaced but still needs some fluid each week. I also tried some Lucas Stop Leak but it did not work.
Can repairs be made without removing the pump. Thx.

Vince

 

This could be just bad or aged O-ring around the neck of reservoir connected to the pump. I believe you need to remove only one screw and snap ring from the neck to get the reservoir out, but syphon the fluid out first.

 

I bet the hose slipped off of the nipple at the radiator.

 

I had the same problem on my 2000 ML320, and it was the O-ring around the neck of reservoir connected to the pump as mbenz80 said. It costed me a few bucks, and the problem was solved.

Good Luck!