johnnyw

My 71 convertible that does not have air conditioning had the heater core hoses both removed and the heater hose was looped back to the intake from the water pump, again this just made a loop in the system. The car didn't have an expansion tank either and I'm wanting to get the heat working. First of all does a non AC 1971 car have a Heater Control Valve? From looking in the Paragon catalog I notice that the heater hose return line goes from the core to a Heater Control valve and then from the valve to the intake. I also notice that the hoses are in some way routed to the expansion/ radiator over flow tank. I have rigged up and overflow tank but can't I just run the heater hoses from the water pump through the heater core and then to the intake and not install and expansion tank or valve in the system. If the car has to have the heater control valve to get the heat to work what does the valve do? I'm going to replace the heater core since I think it is bad due to a spot in the passenger side carpet an I thought I would get the Heater Box seal kit also.
Thanks for any help.

'75

The heater has a blend door inside to get partial air through the heater core and part fresh air depending how much heat you want.

Hammerhead Fred

No heater control valve on the 71.
The core is always hot. Air flow is blocked off in the duct work.

For whatever reason you have an automatic radiator in a 4sp car.
The radiator you have requires no expansion tank. If you go back to the correct radiator for your transmission then you'd need the expansion tank.