HAC Valve

[Cougar]

I hate to do this, but I have to ask yet another question about the vac lines. I have looked at all the previous threads and diagrams for all the lines and cannot find where one line goes. On my HAC Valve there are 5 lines. 4 of them are accounted for and hooked up correctly. The 5th one is a little larger and comes out the front-bottom of the valve. If someone can look at their setup and see if they even have one of these, and if so where does it goes.
This link will show a diagram with the HAC valve for reference.
https://forum.ih8mud.com/showthread.php?t=13031

 

[msummer]

It's been awhile since I've looked at the smog stuff (desmogged a year ago), but I believe the large hose goes to nothing. It is open to the atmosphere to sense changes in altitude via the change in the air pressure.

 

[Blue60]

agree w/msummer...

 

[Cougar]

It's been awhile since I've looked at the smog stuff (desmogged a year ago), but I believe the large hose goes to nothing. It is open to the atmosphere to sense changes in altitude via the change in the air pressure.

Then is the hose that connects to the HAC valve necessary? The one on mine is about 12 inches long and just hanging there.

 

[Pluton]

I figure that Mr. Toyoda[or his descendants]put the hose there for a reason...even if WE don't know why. Why not just leave it?

 

[msummer]

Mine was plugged with a stereo knob before I removed all that junk. I know that offers no insight into the "tube/no tube" situation, but I felt like sharing.

 

[Cougar]

I figure that Mr. Toyoda[or his descendants]put the hose there for a reason...even if WE don't know why. Why not just leave it?

I suppose that would be good reasoning. I guess I'll just let it "hang". Thanks everyone

 

[chitown40]

The is the passageway to 'atmosphere'. It is supposed to be open if it is the one of the bottom of the valve.

 

[Cougar]

The is the passageway to 'atmosphere'. It is supposed to be open if it is the one of the bottom of the valve.

It looks like everyone is in agreement then? It is there to take up space and "suck" in air around the valve. I guess I'll leave it alone and let it do it's thing.

 

[yodaholic]

anything that sucks in air should run thru the filter/air box

 

[Pluton]

anything that sucks in air should run thru the filter/air box

You are correct, o wise one, except: IF that air vent is only for purposes of exposing the aneroid bellows inside the HAC valve to the current atmosphere, in which case the "sucked in air" is not entering the engine, merely the pressure-sensing part of the HAC valve.