VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Windshield Wiper Control-1948 Fleetline

Does anyone make a repro of this or have a good working original for sale?

When I turn mine on, the wipers work as good as can be expected. When I shut it off, I get a constant vacuum leak underneath the dash. Can anyone clue me in as to why it is leaking? Is there a check valve, or some sort of needle and seat that is not functioning? Since I am a day away from removing it, and have never seen one in person, I'm not sure what to expect.

I had a vacuum leak under the dash of my 1950. The leak was caused by yhe slider calve on the motor. There was a little leaf type tension spring to hold the slider valve against the valve. I bent the spring so it had more tension and the leak stopped.
Your slider valve would be on the actual control valve.