I recently ordered a Graf water pump for my W210.065/M112.941. It looks to be a very simple job given that there is no mechanical fan to deal with. While it is working fine, at 150K miles I'm tempted to change it now before I head out on a 1,800 mile road trip just after Christmas. I figure two hours, tops, and that's if I goof off a lot.

(Side note: I ordered the pump from PP and was impressed with the timeliness as well as the price; the box itself is pretty beat up, but the gaskets and the pump survived the abuse.)
At any rate, as I was bored I read though the "Assembling Instructions" that were included with the pump. (Pic attached.) As I make my way through all of the things they discuss, then, at no. 12....hey, isn't that kind of in the WRONG place? Shouldn't it be ... maybe FIRST???
Anyway, Merry Christmas to all of you out there, and however you celebrate this time of year, I hope it proves to be just what you hope for.