56 Heater Control Valve

Daddio

Daddio

Member
Well I'm really PO'd with the heater control valve on my 56 312 Tbird. This will be the third time I've replaced one for leaking. And the NOS replacements keep going up in price .. $65, $85, now $100+.
I suppose it fails due to lack of use, they always seems to start to leak in the fall when I first use the heater.
I see there's a mechanical valve at http://www.classictbird.com/Manual-Heater-Control-Kit/productinfo/18495MK/
Has anyone tried it? I don't like the idea of hot coolant sitting in the heater core ... this car is hot enough as it is.
Also I'm trying to keep it as 'original' as possible.
Anyone have luck with a better made, original looking replacement??
 
I am not familiar with the heater control valves in the little birds, but there are people that rebuild heater control valves. N.O.S. units are what, 60 years old? you cannot expect things like these to last very long the seals and stuff in them were not made to last this long, even when not in use. I had the heater control valve in my '51 Merc. rebuilt about 10-12 years ago and have never had a problem with it. I did buy a spare , that had also been rebuilt, because my car is an early one , and has a control valve that is a little harder to come by than the more common one. I will see if I can find out what I did with the receipt for the valve to let you know who rebuilds the valves. It could be possible that your style of valve is not rebuild able, I do not know , as I said , I am not familiar with the little bird valves.
 
For the fresh air heater (Magic-Aire) system, there were two different types of heater controls used.
It seems the most common type was the system that utilized a vacuum operated water valve on the intake manifold that was connected to a bimetallic control unit in the heater plenum.
Another system utilized a mechanical temperature control valve with a capillary tube located in the heater plenum chamber.
Regardless of which system is used, there is always water/coolant present in the heater core, but in warm weather months when the temperature control knob is set to off, the valve does not allow water from the engine block to enter the heater core. There is no water circulation thru the heater core, it is simply bypassed. But when there is a call for heat by moving the control knob to the right, the valve opens and water from the engine begins to circulate thru the heater core.
I believe it might be detrimental to have a heater core that would be dry part of the time as it might incur more corrosion, but with a heat exchanger that is always filled, the coolant in the system should help to protect the core as long as the coolant lubricative properties are maintained year-to-year AND the water in the system is distilled water (fewer minerals).
 
BTW, you can order components for both types of systems from Concours parts. they have the water valve #B5A-18495A and the associated bimetallic vacuum temp control #B5A-18502. Or, if you have the mechanical type #B5A-18502-A that is used without the water valve. Apparently, there is no core exchange on these, but years ago, you sent in your core and they would rebuild for you. Possibly some of the other resto parts suppliers might still offer this service? Concours does not give prices for the valves, so they must be very expensive.
I did get my mechanical valve rebuilt by Concours a few decades ago and it still works fine.
 
C & G has the B5A-18495A valve for $85 and will rebuild your B5A-18502-A for $150 with a 3 week turn around.
 
Daddio, I have been unable to locate any of my information from when I had my heater control valve rebuilt. The other reply's may give you options. I will keep looking for my misplaced information, if I find it I will post it here.
 
Yea, I think the point about a NOS part being 60 years old, with 60 year old seals and diaphragm, is spot on.
I sometimes focus too much on keeping everything original / NOS, but in this case a new reproduction part may be the answer. It should still look original, but operate for a longer time ... only my hairdresser will know for sure (old guy joke).
A rebuild of one of my 'many' used valves is also a great idea. NOS look with modern innards. I'm contacting C&G now, never dealt with them before.
 
I absolutely agree with not attempting to find a NOS valve as by now I would be concerned that the rubber stopper in the valve would be hard as a rock and would not seal or would break apart inside there so that you would have hot water running thru the core no matter what the controls are set to.
 
Herman Munster said:
C & G has the B5A-18495A valve for $85 and will rebuild your B5A-18502-A for $150 with a 3 week turn around.
Click to expand...

Please be careful here. Go back up and look at my post on 10/27. The B5A-18502A is a "stand-alone" mechanical control and is not used in conjunction with the water valve on the engine intake manifold, however if your system has the vacuum controlled water valve and bi-metallic temp control system, you could remove all that, eliminate the vacuum connections altogether and convert to the mechanical system without any modifications except having to knock out the blanking plate where the mechanical valve is mounted on the firewall.
With the vacuum system, when temperature control is off, the hot water is shut off at the water valve on the engine.
With the mechanical system, there is a heater supply hose from the engine that connects directly to the mechanical valve on the firewall. The return hose connects to the heater core and goes back to the engine. There is a third short hose that runs from the valve on the firewall to the heater core inlet. This is the hot water inlet that is enabled when there is a call for heat. When heat is off, the valve is closed and hot water is not allowed to enter the heater core.
See page 266 of the '56 Ford car shop manual for illustration of the vacuum control system.
 
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