heater core position - The 1947 - Present Chevrolet & GMC Truck Message Board Network

69gmc292 · 01-04-2008, 11:33 AM

i changed out the heater core on my 69 gmc C1500 and was wandering which way the heater inlets went my truck never came with a core and i think the 3/4 inlet is on the top thank you

**john** · 01-04-2008, 01:27 PM

I think you are right.

72ChevyAZ · 01-04-2008, 03:06 PM

How was that whole job (installing a heater core)? I just found out today that mine is leaking. Never tackled this but gonna give it a try. Anyways, here's a bump for ya.

69TowRig · 01-04-2008, 06:47 PM

Quote:

Originally Posted by 72ChevyAZ

How was that whole job (installing a heater core)? I just found out today that mine is leaking. Never tackled this but gonna give it a try. Anyways, here's a bump for ya.

It is not bad, hang the hood from something above (or take the hood off), remove the passenger side hood hinge. Disconnect and remove the fan, then all the screws, carefully pull the box away from the firewall and disconnect the heater flap from the control cable. I did that over a year ago, I think you might have to undo something inside the cab too. It is pretty obvious when you are in the midst of it.

Quote:

Originally Posted by john

I think you are right.

I'm in agreement (3/4" on top).

70GMCer · 01-05-2008, 02:47 AM

Just did mine back in Oct. I didn't have to remove the hood hinge though. Just drop the inner fender down.

68C15 · 01-05-2008, 02:57 AM

in the 5/8 and out the 3/4. otherwise you will create higher pressure in the core leading to eventual blow-out. that is the way the engineers made them.

if you see a car with the same size on both then the feed has a restrictor inside.

01-04-2008, 11:33 AM	#1
69gmc292 Registered User Join Date: Mar 2007 Location: tucson Posts: 71	heater core position i changed out the heater core on my 69 gmc C1500 and was wandering which way the heater inlets went my truck never came with a core and i think the 3/4 inlet is on the top thank you

01-04-2008, 01:27 PM	#2
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: heater core position I think you are right. __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/

01-04-2008, 03:06 PM	#3
72ChevyAZ LWB Club Join Date: Dec 2007 Location: Queen Creek, Arizona Posts: 114	Re: heater core position How was that whole job (installing a heater core)? I just found out today that mine is leaking. Never tackled this but gonna give it a try. Anyways, here's a bump for ya. __________________ 72 Chevy Custom LWB

01-05-2008, 02:47 AM	#5
70GMCer Senior Member Join Date: Apr 2005 Location: Joppa, Maryland Posts: 4,408	Re: heater core position Just did mine back in Oct. I didn't have to remove the hood hinge though. Just drop the inner fender down. __________________ 1997 GMC Sierra Ext 1965 Mustang

01-05-2008, 02:57 AM	#6
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: heater core position in the 5/8 and out the 3/4. otherwise you will create higher pressure in the core leading to eventual blow-out. that is the way the engineers made them. if you see a car with the same size on both then the feed has a restrictor inside.



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