Removed heater box from '81 C10 to replace the heater core, easier than I expected.

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pinballlarry1

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Larry
Truck Year
1981
Truck Model
C10
Engine Size
250 6 cylinder
It went well and quickly. Disconnect coolant hoses. Take out the glove box and ash tray assemblies, removed the 3 control cables, one screw to the defroster Y pipe, and one 10mm head screw on the far-right interior firewall. Burned off the paint and coating from the three 1/4" studs that protrude thru the firewall near the fan motor.
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and the heater box actually fell out on its own.
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It's dusty and dirty but I did expect more debris inside, not too much:
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And here is the weeper, on the return tank end. Nothing obvious why it started, but it was wet in that area:
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Heater core is held in place by a round retainer bar near the hose connections, and a flat rectangular retainer bar on the return tank end.
Mine were rusty and dirty, but cleaned up ok:

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Since these steel pieces are in direct contact with the brass heater core, I plan to wrap them with rubber tape or put heat shink on them to prevent the dissimilar metals from direct contact.
 

89Suburban

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Different world without all the AC crap do dig through.
 

GTX63

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No comparison to pulling the heater core in a squarebody vs say a late model GM truck.
 

fast 99

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No comparison to pulling the heater core in a squarebody vs say a late model GM truck.
Exactly. Used to dislike replacing heater cores in these old vehicles. Being a line tech, working on newer models with a 6-8 hour + flat rate this old stuff is a piece of cake AC or not.

Worst one I can remember was a Nissan Maxima. Every bracket, brace, part came out by itself and lots of them. Forget which one goes back first, start over.
 

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