Testing CJ7 Heater core

[bexarhunter]

I removed my core and flushed it. seemed to be clear and had good flow. I reattached hoses from engine to test core outside of Jeep. Ran engine till thermostat opened and waited to see if core got hot. It didn't. Would I normally feel it get hot as soon as radiator is hot?

 

[TerryMason]

I did some research and you may have your heater hooked up wrong. The hoses should route from the thermostat housing to front of intake, back of intake to bottom of heater core. From the top of heater core to water pump.

If you have your hoses on the heater core the other way around air will be trapped in the heater core, and the heat wont work.

Also, you also need to be sure that bypass hose from the thermostat runs lower than the level of the coolant in the radiator or it will air lock cutting down on the flow and heat radically.


This isn't first hand knowledge, just what I was able to find on the net...