Is the larger or smaller heater hose going to thermostat housing?

Be sure to flush the core from both directions. This will get the maximum amount of crud to get flushed out.
 
From the top of my thermostat housing the tube goes to the top port of the firewall. In the FSM it goes to the bottom port on the firewall. Any ideas why this would be? Maybe the previous owner connected it backwards?? I just picked up this jeep 2003 rubicon and have been following this forum trying to get fluids tuned up first and for most. Working on following the radiator flush thread today.
I appreciate the help!

View attachment 136444
@Black-Bear- my top hose connects to the top Inlet same as your. 2001 4.0.
Did you figure yours out? I’m getting ready to do a full coolant flush and I can change them if need be. Right now, cabin heater works fine, so I’m reluctant to swap them unless I know for sure.
Thanks!

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No difference in which hose goes on top. It is a simple heat exchanger that has no "right" way to flow water direction. Mount the hoses the way you want to. When flushing the heater core, then it is important to flush the water thr8both directions to get the max gunk removed. I would flush backwards first. This will help push gunk out of the core 'backwards' if you flush 'forwards' first you will be pushing gunk into the core, through, then out. Hopefully that makes sense to you.
 
I didn’t wind up messing with them figuring if it ain’t broke don’t fix it. And I took Ejays advise to not splice a tee. It was less work to just pull the hoses off and used a garden hose with a pointed nose nozzle to flush.
 
We are talking about back flushing the heater core. Not how the hoses are normally used.
It appears you misread post #22 and post #25. The only person that has recently mentioned "flush" is you and post #24 which is obviously in response to your post. To be clear, nobody but you in January has been talking about a flush. The recent posts now are all about how the hoses are mounted to the firewall.
 
I just replaced my heater hoses yesterday. They are different sizes (diameters). The ports into the heater core are different sizes.
The larger diameter hose (11/16") goes from heater core top firewall port to thermostat housing.
Smaller diameter hose (5/8") goes from heater core bottom firewall port to the metal tube screwed into water pump.
 
It appears you misread post #22 and post #25. The only person that has recently mentioned "flush" is you and post #24 which is obviously in response to your post. To be clear, nobody but you in January has been talking about a flush. The recent posts now are all about how the hoses are mounted to the firewall.
😲 🙁 😬 🤐
 
No difference in which hose goes on top. It is a simple heat exchanger that has no "right" way to flow water direction. Mount the hoses the way you want to. When flushing the heater core, then it is important to flush the water thr8both directions to get the max gunk removed. I would flush backwards first. This will help push gunk out of the core 'backwards' if you flush 'forwards' first you will be pushing gunk into the core, through, then out. Hopefully that makes sense to you.

Just want to make sure i understand this correct(please don't judge, very new to fixing things alone). the picture from the owners manual makes it seem as if the hose from thermostat to heater core should go to the bottom of the heater core, and opposite for the line from heater core to water pump.
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Confirming it doesn't make a difference? I just replaced my radiator, water pump, thermostat, etc. and mirrored how all the hoses were connected before. I have a leak from the water pump hose, I'm about to replace that and I want to make sure I replace it the correct way and don't run into any issues later.
Any tips and tricks are appreciated.
 
Just want to make sure i understand this correct(please don't judge, very new to fixing things alone). the picture from the owners manual makes it seem as if the hose from thermostat to heater core should go to the bottom of the heater core, and opposite for the line from heater core to water pump.View attachment 186728
Confirming it doesn't make a difference? I just replaced my radiator, water pump, thermostat, etc. and mirrored how all the hoses were connected before. I have a leak from the water pump hose, I'm about to replace that and I want to make sure I replace it the correct way and don't run into any issues later.
Any tips and tricks are appreciated.

I'm also just noticing this Figure is for the 2.5L, but the one posted by Jerry for the 4.0L gives me the same impression.
 
The larger return hose from the thermostat housing connects to the bottom port on the firewall.

View attachment 2694
I just saw this about how the heater hoses are routed from the thermostat to the heater. Jerry's comment and the diagram say the hose from the thermostat goes in the top hole on the firewall. i've had my jeep 8 years now and am replacing the heater hose from the thermostat but it runs into the top hole on the firewall. Has that thing been hooked up wrong the whole time? The heater works fine.
 
I just saw this about how the heater hoses are routed from the thermostat to the heater. Jerry's comment and the diagram say the hose from the thermostat goes in the top hole on the firewall. i've had my jeep 8 years now and am replacing the heater hose from the thermostat but it runs into the top hole on the firewall. Has that thing been hooked up wrong the whole time? The heater works fine.
Answered my own question. doesnt really matter but hooking up to lower allows air in system to bleed out better.
 
For the record, the one posted by Jerry is actually for the 2.4L I just found it in the FSM. View attachment 276209
Not true, the one I posted above in post #8 was for the 4.0. Look at the bottom of the illustration posted there next to where it says Fig. 1. And look at the very bottom of the one you just posted, it's the same one and it still says it's for the 4.0.

And if you look just below where your finger is pointed, you'll discover it says 4.0L cooling with the drawing I posted being part of that section.