It will not move a lot of air, but will a pretty good vacuum. You need a gauge to measure it.

Soapbox time (again)
Everyone who owns a W123 should have, at bare minimum, a MityVac. Please, PLEASE, PLEASE go out and get one before you do anything else to this car. Mine was $26 at Autozone.

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References