First I would pull the vacuum hose off the control valve and hold my finger over the end just in case you should have a split hose. If it holds vacuum and no sound of a leak likely the diaphragm in the control valve bellows has ruptured and no longer can open the valve.



Your valve has failed so doing the following will not harm anything.



One thing you can do is remove some anti-freeze from the cooling system to enable removing the control valve from the heater core. Remove the gasket from the valve so it does not get damaged as you will need to re-use it when reassembling.



Use a hack saw and cut circular just below seam at the largest diameter and above the three vent holes in the bottom half of the diaphragm bellows to separate the top half of the bellows chamber from the bottom half. Remove the top half of the chamber cut the rubber diaphragm from the spindle shaft; tie a wire around the spindle shaft. You will have to pull outward on the spindle shaft as the spindle plunger is spring loaded for the valve to fail-safe in a closed position. You should be able to now blow through the valve if the valve is tied in this open position. Leave the valve tied open and re-install in the heater using the saved gasket.



If the shaft is not sealed around the spindle and leaking you will have to do the following. Pull the spindle out of the valve. Go to a hardware store and buy a cap for a 1/2" or 3/4" copper pipe, clean the well area and the cap with a wire brush or emery cloth, apply some solder paste, with a small propane torch solder the cap inside the open hole, you may have to do some trimming to get a good close fit. You will have full heat this way however you will have heat. You could add a ball valve in one of the hoses to manually control the hot water flow. This will get you home until you can get a new control valve.



marv

I also have a 70 Bronco, and know what you mean by inline valves. My problem is the current control valve attaches to the heater core by bolting the side of the pipe to the core, with an opening in the core to match the opening in the side of the pipe. Unless I do something about the existing control valve, it is stuck shut and nothing I do to the inlet or outlet hoses will have any effect.



I'm not giving any engineering awards to whoever thought of this design.





Jim - Erie Colorado, 1957 Country Sedan

A cable operated flow control valve is used on the old Broncos, or at least there is one on my 1970 Bronco.  I replaced it a few years back with a new one I got at Napa.  Just might fit the older cars too.

If you want to stay with your stock valve, here is one on eBay now with free expedited shipping that you could get by Dec 1 or 2.  It's 60 bucks.  Less than DC I think.

http://www.ebay.com/itm/NOS-1957-1958-Ford-Heater-Water-Vacumn-Valve-/320481798462?pt=Vintage_Car_Truck_Parts_Accessories&vxp=mtr&hash=item4a9e34293e

Jim
Norfolk, VA

"MABLE"
1956 Thunderbird Green / Brown Interior (ZE-XG)

"MEAN GREEN"
1956 Mainline (FG-BE)

This trick is used by several oufits - CASCO for instance has a T-bird version - to simply change the cable control over to directly run the flow control valve. The hardware used is a valve from a 60's /70's (maybe earlier) pickup and in some instances a longer length of cable would be required.

Just for grins I looked up a '65 International Scout on the "RockAuto" site - a 5/8 x 5/8 straight valve, a 3/4 x 3/4 straight valve and a 5/8 x 3/8 pipe 90° valve came up.

I also found a thread on the HAMB where one of the guys was doing this to his '56 Ford sedan.

 
 Steve Metzger       Tucson, Arizona

The fitting in the front of the intake is pipe thread. You could screw a regular sink type shut off valve in the hole and adjust the hot water flow with that. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Here's a pic of the control. On the back side of the short straight pipe is a vertical opening that mates with the heater core. The longer extension goes through the firewall and mates to the heater hose. A 180* bent tube with appropriate opening, brazed to the core, ought to do the trick. Or so it seems...





Jim - Erie Colorado, 1957 Country Sedan

The dash control lever operates a valve that adjust how much vacuum reaches the control valve. It was fairly easy to bypass this by a bit of rubber tubing and a step-down vacuum coupler. So now the full vacuum from the fuel pump goes to the control valve.



The heater control valve is vacuum controlled and is mounted on the heater core The vacuum determines how much, if any, water flows through the heater core. No vacuum and there is no water flowing through the heater core. Unfortunately, with all the vacuum leaks on the new control valve, it is always closed so no water is flowing and hence no heat.



I get in touch with Dennis Carpenter and see what they have to say. But I'm hoping for a short term fix. I'm in Joliet, Illinois right now, just outside Chicago. Unless someone has a better idea, I'll see if I can find any place with old parts for cheap, and see if I can get another heater core. If so, then I'll see if I can find a radiator shop to braze in an open pipe so that full coolant flow is happening all the time. Then I'll have glorious heat. I can adjust temp by off/lo/hi fan speed, or by opening windows.

Jim - Erie Colorado, 1957 Country Sedan

One solution is to get a 90 degree elbow and replace the intake control with it. This will give you heat all the time, but with a shut off you could semi regulate it.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I spent an entire winter in Kansas City in my 57 convertible with no heat. Drive in movies lost their charm even with two of their little heaters it was still freezing! In the spring I was doing a tune up and heard a sucking sound under the hood. Found the vacuum line, plugged it in, and wallah HEAT!

That said I don't know any way to bypass the control valve. I would think it could be done. As I recall the lever push/pulls the control but vacuum pulls the duct open. Maybe you could jam the duct open somehow. Does your heater have the little door on the front? My 56 has one that can be opened to provide more low heat to the passenger side. Maybe that will help for a bit. Good luck. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire