Heater Core question.
 

On the heater core does the top hose go into the intake and the bottom to the waterpump or is it vise versa. I have looked at several pictures and have seen them hooked up both ways. I live in Minnesota so it is gunna have to get hooked up if im gunna use her as a daily driver. Anywho thanks for any help.

Re: Heater Core question.
 

It works either way but one is 5/8 and the other is 3/4 so if they match.....I put my heater core in upside down because I didn't like the hoses crossing.

Re: Heater Core question.
 

Thanks I kinda figured as much. But wouldnt the coolant be hotter coming out of the waterpump? Probly not but just thought I would ask since I live in mn and need it as hot as possible. Thanks again.

Re: Heater Core question.
 

The hot water return is from the top of the engine & going to the top of the radiator, the cool water is circulated from the bottom through the water pump.
The trucks with automatic transmissions had the return line going directly to the top of the radiator from the heater core.
s/t

Re: Heater Core question.
 

I hate to hi-jack this thread but I'm going to due to an issue this brings up in my truck. I get very little heat out of my heater and although I haven't checked my thermostat, I wonder if this might be why I'm not getting heat based on the routing you've described? I have an automatic.

Re: Heater Core question.
 

Yep sounds right to me thanks for the info as always. Never fails, got a question and it will be answered.
Cheers

Re: Heater Core question.
 

You can plumb the return back into the water pump, that is how the manual transmission trucks were set up. Either will work.
s/t

Re: Heater Core question.
 

Ok I have a related question. 72 automatice trans with A/C Heat always on. I have the vacumme controled valve in heater hose that is new but is not closing? But hot water is alway flowing I think through core. Is this wright??

Re: Heater Core question.
 

You should be able to connect it to a known vacuum source and watch it close. If so then it’s up stream on the vacuum side especially since you said the valve is new.
s/t