After putting up with the leak for years, I embarked on a power steering pump rebuild a few weeks back. It looked like a Saturday job and might possibly have been that way for someone. I discovered with the battery removed for visibility and the car on jackstands I could reach the three necessary bolts as well as the adjuster from below. The first step is to back off the two 10mm nuts on the adjuster and then loosen the two 17mm bolts and the one 14mm bolt at the rear of the pump. The problem came in trying to get the pulley off. As I recall, the pulley itself required a 7/8 inch (or possibly one inch?) wrench to hold it steady while loosening the 19mm nut that holds it on. I can assure you that the 19 mm nut served no real purpose because that pulley wasn't going to come off. I'm sure someone will manage to get off the pulley with some special tool but with way over 50 years experience I couldn't do it. I didn't realize that the pulley was actually cast iron until the first piece broke off. Anyway, if you attempt this job yourself I will tell you that the only difficult part is getting that damned pulley off. I will also tell you that they are hard to find replacements for. Assuming you finally get the pulley off, and you must do so in order to remove the mounting bolts, you then simply remove the hoses and the three bolts. Try not to lose the parts of the adjuster in the process. Once off the pump comes across very simply and needs about $6 worth of o-rings to rebuild. Once you have it cleaned, restored and re-painted, start your search for the pulley. It is availble on special order from Germany for about $250 from MB classic parts. Once you get in the new pulley, re-install the pump leaving the three mounting bolts loosely installed and the nuts backed way off on the adjuster. Next attempt to re-install the belt at which time you will find that there is no way to get enough slack. Pull it over the crankshaft pulley and halfway around the pump pulley in the direction of rotation. Then bump the starter and the belt will jump back on. Then consult your parts bag for you fluid and discover the new belt still in the bag. Next, remove the old belt by the same halfway loose and bump starter method. At this point it's a good idea to get yourself a cold one. Next install the new belt using the starter trick again. Pull the adjuster up to about 1/2 inch slack on the belt and tighten all three bolts. Refill system and you are all done.
Only time will tell if I have actually stopped the leak, but the car drives properly again.
Lesson learned: Remove the radiator and the condenser before starting so you can get a puller on the pulley.
Gerry