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Heater bypass valve operation.

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I have just replaced the ugly, old, half there A/C box from my 70 Monte with the "pricey" magic A/C delete box from American Grafitti. I am trying to figure out just when the vacuum controlled heater bypass valve that supplies hot coolant to the heater core actually opens and closes. To the best of my knowledge, it stops the flow of coolant when the A/C is on. Since this is a vacuum controlled valve, it should still work even without the A/C box and wiring hooked up when the control lever is in the A/C position, right??? I ask this because without A/C in the summer, it would be nice to select A/C to stop the flow of coolant to the heater core and keep as much heat out of the interior as possible. Make sence?? There is no sence in installing a new valve without A/C if my theory isn't correct. I have the motor out so I cannot run a vacuum check to see if there is vacuum at the valve when A/C is selected with the air disabled. Anyone have any experience with this?? Thanks.

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All the switching for vacuum controls is done from the dash panel knobs. That stuff you removed and changed won't affect the heater valve operation. Even if it did, it would be an easy fix with some tubing and a valve from the fish-tank store.

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Guest

As long as you still have the original controls and the 2 vaccume lines going through the firewall connected, the heater should work normally. When the dash heat switch is off, the heat control valve is off.

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Hi:

That valve works on vacuum, and turns off the water to the heater core when vacuum is applied to it. With no vacuum water is free to flow thru the heater core.

Hope this helps Ed

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Hi:

That valve works on vacuum, and turns off the water to the heater core when vacuum is applied to it. With no vacuum water is free to flow thru the heater core.

Hope this helps Ed

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Hi:

That valve works on vacuum, and turns off the water to the heater core when vacuum is applied to it. With no vacuum water is free to flow thru the heater core.

Hope this helps Ed

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Guest

That should make it clear...

quick way to get your posts count up wink !!!

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