Classic/Antique Car Repair: Vacuum Valves in-line, controlling headlamp doors / covers. (Vacuum opreated ), vacuum valves, lincoln town

Question
Mr. Dickey,
I Have been told there are a few control valve's in-line (Not the Main valve that move's the door's) about 1.54 in. in dia.
Where are they located and which one is most likely to leak.
This is a 1979 Lincoln Town Coupe. Altho I Think all of the Serie's would use the same valve's.
THANK YOU....
Dale
PS...... I have not worked on this vehicle......
The Local Lincoln Part's Man told me  the vehicl is to old for  looking up info.


Answer
First by Lincoln parts man, I hope you are not talking about the dealer and use the service manager, not the parts dept for schematics, and NO they don't seem to talk to each other.

As for location of valves, I'm not sure on this model, but just trace vac hose back from actuator module and you'll get it.