Heater Core question. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Grapdawg · 03-30-2009, 07:19 PM

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.

PanelDeland · 03-30-2009, 07:33 PM

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.

Grapdawg · 03-30-2009, 08:36 PM

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.

Sport/Truck · 03-30-2009, 08:53 PM

Quote:

Originally Posted by Grapdawg

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.

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

Brad · 03-30-2009, 09:18 PM

Quote:

Originally Posted by Sport/Truck

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

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.

Grapdawg · 03-30-2009, 09:18 PM

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

Sport/Truck · 03-30-2009, 10:18 PM

Quote:

Originally Posted by Brad

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.

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

gary2232 · 03-31-2009, 04:03 PM

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??

Sport/Truck · 03-31-2009, 04:40 PM

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

03-30-2009, 07:19 PM	#1
Grapdawg Driven a 72 Join Date: Nov 2008 Location: Minnesota Posts: 166	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. __________________ 1996 GMC JIMMY 1972 CHEVY C10 LWB My 72 c/10 Build: http://67-72chevytrucks.com/vboard/s...d.php?t=318729

03-30-2009, 07:33 PM	#2
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	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. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

03-30-2009, 08:36 PM	#3
Grapdawg Driven a 72 Join Date: Nov 2008 Location: Minnesota Posts: 166	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. __________________ 1996 GMC JIMMY 1972 CHEVY C10 LWB My 72 c/10 Build: http://67-72chevytrucks.com/vboard/s...d.php?t=318729

03-30-2009, 09:18 PM	#6
Grapdawg Driven a 72 Join Date: Nov 2008 Location: Minnesota Posts: 166	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 __________________ 1996 GMC JIMMY 1972 CHEVY C10 LWB My 72 c/10 Build: http://67-72chevytrucks.com/vboard/s...d.php?t=318729

03-31-2009, 04:03 PM	#8
gary2232 Registered User Join Date: Jul 2008 Location: Tracy Ca Posts: 171	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??

03-31-2009, 04:40 PM	#9
Sport/Truck Sierra Grande Club Join Date: Jan 2007 Location: New Mexico USA Posts: 2,433	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 __________________ 1971 GMC Sierra Grande, 1/2 ton short wide, original 4 bolt 010 020 block & heads. (matching #'s). 383 stroker, SMI q jet 750 cfm, Lunati Voodoo 60102 cam, Scorpion roller rockers, Spin Tech pro street mufflers with X pipe.



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