2004 F-150 Heritage 7700. Vehicle came to me with heater lines re-routed, I assume that the heater core leaks. I’ve looked around for a schematic and can’t find one. I did find out that the chrome tube thing somehow is a heater connection part. I assumed that was the disconnected bi-fuel. Anyway, I’m in the process of reconnecting the coolant lines and it seems to me they should run as I have marked in this photo. Red from block and green marked as return. I can’t see why this wouldn’t work, even though it doesn’t connect to the chrome tube thingy. Thoughts?

 

I took two pictures yesterday, for you or another poster asking the same thing
The pictures are not real good at showing where the hoses go
Did notice for you, that the front pipe coming from the intake manifold on the motor, goes to the drivers side heater core tube
That hose comes up from the manifold, turns forward, makes a Vee and then goes back to the core
The other hose (that comes from the rear pipe by the rear of the intake manifold) goes to the passenger side heater core tube
That hose comes up, goes forward and then Vees back to the core as well
Damn ignorant job replacing the heater core on one of these generations of truck
That is what I was thinking too (the core most likely leaks)
Hope these photos and the description helps

 

1997 5.4 w/ aluminum manifold

 

 

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