W140 95 S420 ACC air intake drain
 

I notice that a short piece of hose that appears to be some sort of drain for the ACC air intake tray above the blower is broken at the bend. If I have all of what broke off, it's a length of hose about 4" long, pinched at the far end and wrapped in wire loom. Is this a critical piece? Is there more than 4" to it?

Thanks,
Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Same as mine
 

If its the piece I think you're describing, its identical to the drain on my S500 W140. Actually, I think there are two...
Anyway, looks to me like they drain off any accumulation of water that may make its way into the air intake system from outside.
Yes, only about 4 inches long with a 90 degree bend in it. Mounted in a hole on the front side of the air system.
Its pretty hard to get the air plenum into position without pinching these things against a brace; that, and some age probably causes them to break.
Not sure how "critical" they are, but the pinched end (lets water out, restricts air flow in) tells me the designer didn't want air coming in that way. Maybe it would bypass some of the recirc function of the climate control?
Why not replace them? Only a couple bucks a piece. 5 minute task.
Hope this helps, KenP

When I first got my car . . . .
 

I replaced the 'filters' (pre and main) and that little tube was pugged with debris. This cause the water that enters from the 'air-holes' in the hood to accumulate and then, if enough, overflow in the pre-filter/blower assy. Not a good thing.

But if I remember correctly, mine is not bent: it hangs straight down and MUST align properly with the drain hole for it to drain correctly. When replacing the air-plenum, line up that tube first.

You certainly can replace it and that's probably the best thing to do but if the rubber is still good, then clean it.