vacuum leak at heater valve?

[Mike70gtx]

The valve that lets the hot water into the heater will only open manually. It opens by a vacuum line. The lines are new. Could I be losing vacuum in the valve itself or is it just stiff.
Just trying to reduce vacuum leaks and was wondering if it is possible for one of the valves to leak.
Thanks
PS. If so do local parts stores have them

 

[Buick From Hell]

Unless there are different ones than mine, I believe the heater core water valve is operated by a wire-cable(?)... but the air-doors ARE operated by vacuum. As long as the doors are operating as they should, you shouldn't have a vacuum leak!

 

[1984grandnat]

My car has a vacuum leak behind the heater/AC panel that you can audibly hear, but only when the temp control is turned all the way to hot. My fix: leave the control on cold, hehe. Don't know about the valve in the water line, though.