Heater hoses on '56 Fairlane

[Ford Freak]

Hey guys! My '56 has a new heater core in it, but only has the hoses on the 2 nipples closest to the fender. There are 2 other nipples coming out of the firewall on the other side that no hoses go to. I saw a pic online w/the hose routing. What was Henry's reason for this? Thanks in advance! F F

[Hot Rod Reverend]

There were two options for coolant control feeding the heater core. The most often supplied valve was one that was vacuum controlled and was attached to the intake manifold. A long vacuum tube went back through the firewall to the heater controls.

The "nicer" valve was the one you are describing on the firewall. It actually has a capillary tube that was in the heater plenum to sense the heat coming from the heater core and fluctuate the level of coolant (and therefore temperature) coming through the heater core. Of course, you need to be a little bit of a magician to know the temperature degrees associated with the dash lever that controlled the setting. You had a Low and a High setting with the word TEMP in between.

[Ford Freak]

Thanks HRR. My car has a 351C in it that is out of a '72 Mustang. No valves on the manifold. I have 2 hoses going into the heater core, but they don't get hot. Hence, no heat. ????

[miker98038]

Yes. Now my understanding was that “firewall” valve was inline with the heater and controlled the flow. But in that case I’d think you’d always have heat.

Having had valves failed in the closed position, I know the result is cold hoses. Any chance the core is plugged? Even though it’s new?

[Ford Freak]

Originally Posted by miker98038

Yes. Now my understanding was that “firewall” valve was inline with the heater and controlled the flow. But in that case I’d think you’d always have heat.

Having had valves failed in the closed position, I know the result is cold hoses. Any chance the core is plugged? Even though it’s new?

I guess anythings possible w/this car! Something must be plugged. I will check it out tomorrow.

[Ford Freak]

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Found the problem! There is an inline shut-off valve in the hose going to the heater core. It was closed, so something was plugged after all. Why would anybody want to shut off the coolant to the heater?? I figured it was probably "something simple" like it usually is w/me, and it was. Thanks to all that responded! - F F

[miker98038]

With it open it’ll blow hot air at speed in the middle of the summer. They sell those for Thunderbird’s as kits to replace the hard to find (that work and don’t leak) vacuum valve. They include a cable to operate off the original temp control

Your temp control, that “other” set of missing hoses probably failed, and the simple way out was to add the shut off.