Do you have a backflow/check valve on the engine to keep hot coolant from going all the way to the heater? Your inlet comes off the water pump at the front and flows to the Ranko where it stops, but the other end is on the motor, and as the engine gets hot it would start to heat up the water in the hose, which would flow through the heater until it gets to the other side of the Ranko. If you put a check valve on the motor you keep the hot coolant from flowing to the heater.

Aaron

[quote="Chris Smith" post=13861]What could cause radiant heat to come from the heater core with the heater off? It has a fresh rebuilt valve and the hoses are installed correct. Its a 54 Hornet

Make sure that the wire didn't pop off the heat selector lever on the dash or the ranco valve.

The cable is attached at both ends. I like the check valve idea so I will have to hunt for one and try that out. thanks

If the hoses are correct and the cables are connected, then your ranco valve is not closing. Try manually moving it to make sure it's not stuck open. The system is pretty simple, when the valve is open you get heat, when it's closed you don't.

None of my cars ever needed a back flow valve, the original design works fine.

Just as Eddie said, your Ranco Valve is not closing. When Ranco Valve is closed there can not be any back flow. Your hoses should be hooked up as follow. The right outlet on the head to the lower connection on the rancho valve, upper connection to the top of the heater core and the bottom heater outlet to the water pump. Remember water pump is pulling the water back and can not have a back flow. Walt.

Here's a picture to verify your hose routing.

[quote="Walt and Margaret Mordenti" post=13876]Just as Eddie said, your Ranco Valve is not closing. When Ranco Valve is closed there can not be any back flow. Your hoses should be hooked up as follow. The right outlet on the head to the lower connection on the rancho valve, upper connection to the top of the heater core and the bottom heater outlet to the water pump. Remember water pump is pulling the water back and can not have a back flow. Walt.

I am now confused re the hose routing as this is the third version that I have seen over the last year or so. I am not doubting you Walt but for a relative newby with stepdowns I can easily be confused.
Is the main issue re routing, relate to the direction the water flows through the ranco value (sucking the water through the top ranco outlet) rather than through the heater core?

Thanks in advance for the clarification

Alistair

Thanks for all the tips. I will pull the valve and look it over.

The water is controlled by the rancho valve. My way to have the hoses is the only way you can not get heat with rancho valve closed. I can drive my car in over 100 degree weather and with cowl just cracked opened, there is no heat coming in. The reason the cowl is just cracked open is for the air condition to work as designed. All new cars take in outside air when AC is turned on, if not you will get water being blown out as the condenser freezes up. Walt.

Thanks Walt - I have re-routed the hoses as per your instructions so will see if a difference is noticed as there has been a small amount of heat coming through when shut off - fingers crossed.

[quote="John Forkner" post=13877]Here's a picture to verify your hose routing.

I just checked my 51 S6 and it's the same as John's.

If I am reading Walts hose routing correct, It is different than the posted pictures. Mine are routed the same as the picture.

Check with Lance Walker, as he is THE expert on this, as he rebuilds them.

Ray, The routing of the hoses John Forkner provided is correct. However heat may be coming in due to a punctured ether bladder in the Ranco. You can replace a seal but if the bladder is ruptured, it's no good. Of the many,many of Rancos I have repaired over the years, this happens about 10% of the time I get one to repair. Nothing you can do except get another bladder of get another Ranco altogether.