Need help with a part for a 1997 Ford E350 6.8L triton V10, A/C vacuum control valve. what does it do?

I think that it is bad because when i turn the knob on my a/c to the dash level vents it just comes out the vents on the dash and on the floor, i just replaced all of the bad vacuum line and im still having this problem. could this be the cause and how can i tell if its bad? also please list any other parts store parts numbers that you can find.





Thank youNeed help with a part for a 1997 Ford E350 6.8L triton V10, A/C vacuum control valve. what does it do?
Suction valve is the problemNeed help with a part for a 1997 Ford E350 6.8L triton V10, A/C vacuum control valve. what does it do?
You just have to trace the lines and check for them holing suction.





I could also be a diaphragm valve , or the rod that connects the valve to the vent doors in the duct work