OT- gmc heater core question?

Ray · Jan 7, 2012

I bought a 1971 gmc 5500 series truck with a v6 gas engine.The heater core was leaking and the previous owner unhooked the hoses and mashed the ends of the heater core shut.Which end goes up on the new heater core,the 1/2 inch or 3/4 hose end? Where should the hoses hook to the engine?
He hooked the heater hoses together and i'm not sure which one goes to the top.Thanks.

LJD · Jan 7, 2012

Inlet is 5/8" and outlet is 3/4"

Anonymous-0 · Jan 7, 2012

You might luck out and take the hoses off of the engine and see what size outlets are on the engine. chris

Ray · Jan 7, 2012

Which connector is on top of the heater core? The 3/4 or 1/2 in.?

Wayne in MN · Jan 7, 2012

Outlet on top (3/4") always.
If you reverse the coolant flow there would be air pockets in the core and poor heat transfer.

Ray · Jan 7, 2012

Thanks!

OT- gmc heater core question?

Ray

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LJD

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Anonymous-0

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Ray

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Wayne in MN

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Ray

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