I got no vacuum at my water control valve?
Apparently you have the bimetallic vacuum thermostat valve in conjunction with the vacuum operated water control valve. (thermostat valve is located in the heater register under the dash and the water valve is located on engine intake manifold).
If so, the way it works is that vacuum is pulled from the engine (intake manifold) via metal tubing to a rubber hose that penetrates the firewall and terminates at a nylon "tee" fitting. One end of the tee goes to windshield wiper motor and the other end has a hose that connects to the vacuum thermostat valve.
WHEN the temperature control knob is set to "heat", the vacuum thermostat valve opens vacuum to flow thru the thermostat valve to another little hose that goes back out thru the firewall to the water valve on the intake manifold. The vacuum pulls a plunger inside the water valve to open hot water flow to the heater core.
Soooo, if you wanna check vacuum, Run the engine, set the temp control knob to "heat", pull the vacuum hose off the water control valve on the engine and measure the vacuum pull coming thru the HOSE, not the water valve.
If no vacuum is detected by your guage, work your way back to the thermostat control valve and check the output hose there. Still no vacuum, pull the inlet hose off the thermostat control valve and measure vacuum pull from the HOSE. If no vacuum is detected, possibly your dual-action fuel pump has a busted vacuum diaphragm.
BUT do not assume so.
Bypass the vacuum booster on the fuel pump by connecting vacuum DIRECTLY from the metal tubing (originating at that square brass fitting on the intake manifold) via a rubber hose to the inlet of the thermostat control valve under the dash. Now select "heat" at the temperature control knob, then ONCE AGAIN go back to the water valve and check for vacuum at the HOSE.
If you NOW have vacuum, the thermostat control valve is GOOD ! Replace your dual-action fuel pump.
The only other thing that could be causing a problem is a cracked rubber hose (or disconnected) which is leaking all the vacuum.
Look at page 266 of the '56 Ford CAR shop manual to see illustration and read how the system works.