Heater valve placement

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Aug 29, 2014 | 02:45 PM

ungerp

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Heater valve placement

Installing my heater hoses to the core on my 55. I presume the one from the water pump goes to the bottom inlet on the heater core and the one from the manifold goes to the top. So in which hose does the heater shutoff valve go in the top or bottom hose? I would think the bottom hose from the water pump.

Aug 29, 2014 | 04:15 PM

52 Merc

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From: Burbank, WA

Quote:

Originally Posted by ungerp

Actually, it's the other way around. The water pump pulls the water from the bottom of the radiator and also through the heater core from the intake manifold, just before it goes back to the rad. The shutoff valve should go in the line from the intake so hot water isn't entering the core. The hot water from the intake goes in the bottom of the core and the line back to the pump is the top core fitting.

Aug 29, 2014 | 06:23 PM

rhopper

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From: peyton, colorado

Wayne's right! Vintage Air told a story awhile back about heater valves in the return line. The suction of the pump would pull the valve open, letting hot water flow through the heater core when the heat was off.