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Heater core shut off valve




I have heard people mention installing a shut off valve for the heater core to prevent heat from coming out of the vents, and the car becoming an oven.

But does anybody have an explantion on how to do this or a diagram that would be great thxs.
I recently did this on my 79. All you need to do is go to a local hardware store, pick up two shut off valves with fittings. Then just cut your heater hoses at a good location and install the fitting holding the hoses with clamps. Be sure to get the proper size fittings. Mine were 5/8 and 3/4". This seems to help cool the interior some as you don't have hot water circulating thru the heater core. Come cool weather, all you have to do is open the valves.
I installed two valves in case of any backflow. This ensures that no hot water enters the heater core.
In a stock setup, there should be a control valve on the supply hose coming off the manifold. It is vacuum controlled by a switch mounted on top of the air distributor box behind the passenger dash pad. The vacuum line exits the firewall to the right of the distributor in the same grommet that the vacuum source line is fed to the heater controls. When the temp control is moved off the full cold position, vacuum is released to the control valve which then opens and lets in the hot water.

Key to proper operation is a good vacuum switch, properly adjusted, and a good control valve.

Better operation guaranteed with Roy's method!

Either way, this is a must have or you will always have hot air blowing out the lower vents

OK thanks guys got my shut off valves today gonna put them in sometime this week. Also got some mufflers for my side pipes, they were starting to hurt my ears although it sounded awsome.
hehehe cops didnt like it though.

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