Heater return flow
 

Hello, Should the coolant to the radiator stop with the heater off?
I just corrected the hose routing and was looking in the radiator and the flow never stopped.

Re: Heater return flow
 

What do you mean by ‘corrected’ it?
Describe your heater coolant flow now.

Re: Heater return flow
 

If you mean the coolant circulating in the heater core, it wont stop circulating unless there is a valve in one of the hoses. Preferably the hot water hose coming from the top of the engine. A lot of vehicles do not have a shutoff valve. Mostly the ones with the standard heater. The fan switch is the only control.

George

Re: Heater return flow
 

Hello, I did have the heater core inflow from a connection on the water pump, now it is connected to the intake manifold.
I think that there is a vacuum controlled valve in that line that is not working 'if' it's supposed to close at some point.

Re: Heater return flow
 

A pic of your hose set up would help a bunch.

Re: Heater return flow
 

Might mention your vehicle and year. Some had valves. Many didn't. My 75 C10 with AC has the heater plumbed like yours is now but never had a valve. Coolant flows all the time. Heat is controlled by a flapper in the in-cab part of the climate system. Flapper controls how much air flows through the always hot heater core.

Re: Heater return flow
 

Hello, Geezer, I am thankful for your help as I am on this site quite a lot and think of your input highly.
I have been meaning to post pictures of my truck for years and have not done so for the simple reason that I have not made my daughter do it (one day I will).
My phone plugs into the wall. When I type my fingertip hurts and this computer is at my work.
After I rebuilt my engine, I connected the heater hoses where I removed them from (core intake at water pump thru piping and return at radiator) even Thoe the pictures in the book showed otherwise. After working on the AC and heater I did not have adequate heat.
I now have the heater core intake hose connected to the intake manifold by the tstat housing, in that line there is a pipe system that I think is a vacuum controlled valve that is not stopping the flow. That is what I am trying to learn, does the flow stop at some point in the heater if it is switched off at the controller in the cab ?

Re: Heater return flow
 

Hello, I have a 72 350 auto with air.

Re: Heater return flow
 

1972 should have the hose from the intake going TO the heater core and the RETURN should be to the radiator. Any fittings going into the water pump is suction. So if something has changed on your 72, return could be to the water pump but it has to be fed by the intake fitting regardless of a shut off valve. The vac control valve should shut off hot water flow when the AC comes on which is controlled by the A/C/heater control piece under the radio.

Re: Heater return flow
 

The hoses are different sizes. It should be clear which one goes where.
George