heater control panel, vacuum leak?

[tigmaned]

just wondering if when any one else with a old C4 vette has this. when i slide the control lever to either vent, heat or defrost i hear a pretty strong vacuum leak, but should i?? i know things are moved with vacuum power, so is this telling me its time to get a new control? or is there a way to repair them?
Thanks for looking.

 

[3dale1]

Maybe you have a couple of chewed or frayed/rubbing vacuum lines that control those functions? My 85 had this problem, and instead of putting in new lines from the panel to the actuators, I just spliced them. (Real tight in there) Good as ever!

Also, I believe that a small release of air when the slide lever is moved from position to positions is normal.