Yes im sure about your valve question. The operation you describe sounds normal from my experiences.
I adjusted the steering box while I was resealing it and it was on the bench. Never did it in the car. However since the MB proceedure on the CD show taking torgue readings from the steering wheel, I assume that it is possible to adjust it without removing it.
I got too many cars!! Insurance eats me alive. Dave
78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k