Where do the Heat / AC controls get vacuum

[Some Car Guy]

You can get the fitting you need for a manual brake car from mopar mall. That’s where I got mine. They told me it is rare for a car to have ac and manual brakes, something I quickly learned when searching for that tee. I wanted a correct single outlet. You could use any vacuum tree though to accomplish this.

you run hose to the line with a fitting on it so you can change the under hood hose anytime since it gets heated up.

 

[dspur]

You can get the fitting you need for a manual brake car from mopar mall. That’s where I got mine. They told me it is rare for a car to have ac and manual brakes, something I quickly learned when searching for that tee. I wanted a correct single outlet. You could use any vacuum tree though to accomplish this.

you run hose to the line with a fitting on it so you can change the under hood hose anytime since it gets heated up.

Anyway, you mentioned “tee” so I’m wondering if that branches to what would have been the power brake booster? In this case tho one vacuum line with the fitting on the engine side as you describe?
I’ll check with Mopar mall, have purchased a good bit from them.
Thank you

Are you talking the vacuum supply from the engine? That connects to the back of the dash switch, into the little vacuum manifold that holds all the lines together coming from the heater box. Run a line from a full time vacuum port on the carburetor base or the vacuum hose tree on the intake manifold if it has one.

If you are completely unable to figure out where your hoses go on the box itself, you can figure it out with the dash switch and a vacuum pump on the work bench. The hose harness that goes with the heater box somewhat gives you some "clues" based on the length of the lines, and the color stripe on the hoses (if you have an original set). Yellow striped hoses retract the particular vacuum pot and the red hoses extend them (yellow connects on back of vacuum pot, red on front). With a vacuum pump connected you can bench test the box and connect all the hoses and use the switch to set the different modes, and make sure they are correctly hooked up; IE make sure defrost pots actuate when you hit defrost, vent pots actuate when you hit A/C, etc. Also make sure they retract for the ones with both hoses when you change the modes.

Would this be the vacuum port to use, only one I could find? Rebuilt Carter 4711S that came with these engines. Also is there a specific hole for this that goes through the firewall ? (Gonna replace the Edelbrock on it now when I get to that point). I truly appreciate all of your help.

 

[Some Car Guy]

Anyway, you mentioned “tee” so I’m wondering if that branches to what would have been the power brake booster? In this case tho one vacuum line with the fitting on the engine side as you describe?
I’ll check with Mopar mall, have purchased a good bit from them.
Thank you

Would this be the vacuum port to use, only one I could find? Rebuilt Carter 4711S that came with these engines. Also is there a specific hole for this that goes through the firewall ? (Gonna replace the Edelbrock on it now when I get to that point). I truly appreciate all of your help.

View attachment 1522188

Yeah it has a single 1/8 barb for the ac line when you don’t have power brakes.

that’s the ported line for the vacuum advance

i dont think the avs has a manifold vacuum port.

 

[LowBikeMike]

Here is what the fitting looks like on a manual brake AC car. Edelbrock manifold, but fitting should be the same.

 

[dspur]

Ok yes that is on the back of my manifold but a bit mangled above the nut and I was not sure that was for vacuum.

Thanks much!!!!

 

[LowBikeMike]

While I'm at it, here's where it goes through the firewall. Just to the drivers side of the water valve.

 

[dspur]

Great. Truly appreciate that. I have just ordered the nipple and new vacuum lines (mine are ok but given they are 50 years old plus and hard to access not taking any chances). This helps tremendously.

 

[Daytrepper]

Anyway, you mentioned “tee” so I’m wondering if that branches to what would have been the power brake booster? In this case tho one vacuum line with the fitting on the engine side as you describe?
I’ll check with Mopar mall, have purchased a good bit from them.
Thank you

Would this be the vacuum port to use, only one I could find? Rebuilt Carter 4711S that came with these engines. Also is there a specific hole for this that goes through the firewall ? (Gonna replace the Edelbrock on it now when I get to that point). I truly appreciate all of your help.

View attachment 1522188

That's the vacuum advance port for the distributor.

That carburetor doesn't have a full vacuum port, as it would be opposite the vac advance port on the other side of the big port in the middle, which is generally for PCV valve.

Edelbrock carb will generally have both. Also most of them have a plug on the back of the throttle body where you can connect a vacuum tree fitting, for power brakes, full vacuum for A/C, etc. I have an Edelbrock with A/C vac connected to the full vac port on front, then power brakes connected on the back of the carb.

As mentioned you can tap into your manifold for full vacuum if it has an available plug, or port.