View Full Version : 4 port heater on/off valve

02-23-2016, 11:46 PM
All, Not sure if you have noticed but the engine coolant will pass through the heater on/off valve in the side pod even when closed and radiate heat. In some cases will reach the heater core and then the AC needs to work to overcome the heat. A small mod I did was to move the valve from the side pod to the engine bay. The coolant must continue to flow past the thermostat on an LS engine to work properly. The 4 port heater valve when in the off position allows the coolant to circulate back to the thermostat built within the water pump.

I purchased the valve at:http://www.oldairproducts.com/pdf/flipbooks/2013_flipbook/flipviewerxpress.html (note: Part #25-1018 or Part #25-1019 depending on if you want a push or a pull to close/open the valve)
I found these hoses that worked for me: http://www.summitracing.com/parts/dac-70001 (note: you may need a hose adapter as the heater coolant ports are 5/8" and 3/4")


03-17-2016, 04:14 PM
Very nice modification.
I personally went with the electronic version of the valve, My AC controls are in a center console, no need for a cable.