MB did not rid of the vacuum reservoir - its installed on my 1995 E300D behind the passenger fender liner and is linked via a brick red vacuum tube that tees off from the Y junction behind the brake booster.

Mine was disconnected because the line was cut, I repaired it with some rubber tubing while I was doing blower motor R&R. It smoothed out the yank of transmission shifting to a firm surge of power and also helped the dashboard flaps to work quicker (I think)

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)