Trico Folberth air pressure wiper
 

My 1945 Ford have these installed and work very well!
But the pipeline is connected to de vacuum under carb.
NO Air pressure... :confused
Are WW2 or post WW2 these motors?
Regards

These were still available as a part for a Wagner log stacker back about year 2000

They are original to a lot of the M-series trucks from the 1950s. The new ones now are made from plastic. Interesting that they work well on vacuum.

Vacuum wipers
 

I have seen these style of Motors running on vacuum. If I remember to convert from air to vacuum the seals on the piston need to be reversed and the restriction needs to be removed from the run port. There may be something I have forgotten, it’s been almost forty years since I converted one!