Heater tap vacuum not working

[VSPantha]

Hi everyone.
I just replaced the heater tap in my car, replaced the foot long vacuum tube from the tap to half way along the ds manifold, turned the engine over and changed the temp and direction settings on the HVAC.
The HVAC directional ports have vacuum, and are sucking and changing from windscreen to face to feet etc... but the hot cold actuator is doing nothing to the heater tap.
The metal rod is conneced and working, and pressing on the little cut off valve when it's on cold. Just no movement in the heater tap itself.
I tested the tap before I put it in and the valve works (it should as it's brand new)... but I have no idea where to start troubleshooting.
Could it be the cut off valve near the metal rod that's failed? What's the procedure to check that?
Thanks in advance

[VSPantha]

I found a check valve with no hose on it... can anyone let me know what this one is for?
Also got the heater tap working properly now... readjusted the cut off valve as it wasn't quite in as fas as needed.
Any ideas why there's a valve in my engine bay with no hose on it???

[StockoVRWagz]

Im pretty sure that valve is part of the the fan/air control for direction system (demister,face,feet)

[VSPantha]

But what is supposed to be hooked up to it? Couldn't see any other tubes behind there?

[delcowizzid]

that is the vacuam feed to inside the car to control all the heater and vents should goto the little nipple underneith on the elbow that the throttlebody is on it goes through that one way valve then has a tee peice with one hose going insied the car and one going to the vacuam ball under the front of the car

[VSPantha]

Hey Delcowizzid,
Thanks for your post. I had another look under the bonnet... here's what I can see...
From the vacuum ball, goes to a check valve, then to a t-piece... one branch of the t goes to another check valve then into the firewall, the other branch goes into another spot in the firewall. Other than that there are the bigger tubes for the brakes and the one that goes under the manifold to the front of the throttle body for the map sensor. Couldn't see anything else that it could hook up to??
I tested the HVAC positions, everything changes properly between windscreen, recirculate, face etc, and I can't hear any vacuum hiss on any of the settings. The heater tap now shuts off (FINALLY have cold air con!) and nothing out of the ordinary seems to be happening. In saying that I'm sure that the valve is there for a reason so I would like to find out what it's supposed to be piped up to.
I checked my Ellery's manual (I soooo need to get a Gregory's instead) and it only shows 2 vac tubes that should be going thru the firewall... one to the vacuum source and one to the heater tap?
My car is a V8, so I'm not sure if the diagram there is only for the V6, but I'd think that the standard air con between them is pretty much the same.
One other thing I forgot to mention earlier... if I have the fan on highest setting (4) and the position on recirculate, it blows pretty hard, but then if I accelerate it seems to blow harder whilst under throttle, then if I let the throttle off, it goes back to the normal recirc 4 amount... but doesn't do this all the time... is that normal or just wierd?