Vacuum line from heater control valve

[JeffW]

I've spent a good part of the day bypassing a leaking heater core. After all that, I see a vacuum line that is coming off the bottom off what I believe is the heater control valve (fairly large brass part that the shorter heater hose attaches to). That vacuum line is not attached to anything. I must have knock it loose messing with the heater hoses. Where does this line attach ?
Strange thing is the car seems to run great with good O2 numbers and no KR at 21psi boost running alky.

Thanks,
Jeff

 

[1970gsx]

That vacuum line runs into the passenger compartment to the heater/ac control in the dash. It enters the pass. compartment under the area of the blower motor.

 

[JeffW]

Why would the AC still work if that line connects there. Not doubting you, but it seems it would kill the AC

 

[Nick Micale]

The vac line will not "kill" the A/C, but your vents or heater control valve may not work correctly.

 

[JeffW]

I found that the vacuum line had been cut in half. I though the line was awfully short coming off the heater control valve. I found the other half of the line coming out from under the AC components near the firewall (I guess the blower motor). I don't think I actually did this messing with the heater core bypass.

My A/C has never blown out the vents very hard like a newer car might. I spliced the line back together and now my AC blows much harder than it ever has in the 7 years I've owned the car.

 

[Wahoo]

Anyone have any pictures of where the vacuum line comes from thats connected to the heater control valve?

My car is a hot air, i dont know if that makes a difference.

What about from inside the car, how would i find the vacuum line, most likely i need to replace the entire thing...

 

[Nick Micale]

There are 2 small plastic vacuum lines, one is to bring the vacuum source into the car for the control panel.

The second plastic line is from the AC control panel to the heater control valve.

The heater control valve is normally open, and vacuum is needed to close it.

A simple solution is to by-pass the heater control valve in the summer, and connect it again in cold weather.

 

[Wahoo]

There are 2 small plastic vacuum lines, one is to bring the vacuum source into the car for the control panel.

The second plastic line is from the AC control panel to the heater control valve.

The heater control valve is normally open, and vacuum is needed to close it.

A simple solution is to by-pass the heater control valve in the summer, and connect it again in cold weather.

Normally open as in open to flow of radiator fluid?

Then wouldnt i want vacuum hooked up for summer to close the valve, and then winter pull the vacuum line off to allow it to open?

Id like to hook everything up properly like how the factory set it up, because eventually id would like to get the AC and heat going properly.

Whats the best way to be able to inspect the ac control unit and the heat control unit? How do you get to them to change the vacuum lines?

Thx

 

[Wahoo]

Bump

 

[Wahoo]

Bump