The GMC CCKW

Hi,
Installed two vacuum motors for the wipers, but when I switch them on the speed is very fast!
The motors are the original one lever ones, is there an way of reducing the vacuum level to slow them down?

Seems like you need to instal an adjustable valve in the vacuum line.

David

Interestingly, the early style wiper motors had two knobs (one for on/off and one for speed control). Later motors had only a single on/off knob. Options might include adding a vacuum valve under the dash, or perhaps in the engine bay where the vacuum line connects to the manifold.

Perhaps something like this?? https://www.menards.com/main/outdoors/w ... 863&ipos=1