Anyone have a picture of their heater core hoses?

[Leroy_TJ]

Need some help, I changed the heater core and hoses out today.
I put the new hoses on like the old hoses came off.
I double checked with the FSM and according to the manual the hoses are crossed. Does anyone have a pic of their heater hoses I can use for a diagram ?
I have the manual pic , but don't understand why the hoses that came off were different than the manual.
The jeep has 137000 miles on it and the hoses I took off looked like the original ones.

 

[Chris]

Looks like they are indeed crossed.

 

[pagrey]

If you take a look at the heater core it makes zero difference.

 

[Leroy_TJ]

@Chris Looking at the manual I agree, but what has me confused that's the way the hoses came off. I want the hoses to be right I will swap them according to the manual.

 

[Chris]

If you take a look at the heater core it makes zero difference.

I was thinking that right after I posted, that I’m not sure it would actually make any difference at all.

 

[Leroy_TJ]

It's my OCD

 

[pagrey]

If I had a good case of OCD I'm sure I could think of a few reasons why they should and shouldn't be swapped.

 

[dbbd1]

It's not OCD, it's OCG. Because it's a gift.

Mine are like yours, not like the FSM.

 

[duncan2plus2]

My hoses are like yours in the pic. Were like that when I bought the TJ recently. Hoses are MOPAR hoses and possibly original, but the clamps look newer. Since the FSM clearly shows them crossed, I'm going to flush the heater core and re-install the hoses per the FSM crossed installation to see if it makes any difference.

 

[Plumber1]

I was thinking that right after I posted, that I’m not sure it would actually make any difference at all.

I was thinking the same thing, it's just a simple in and out

 

[Chris]

I was thinking the same thing, it's just a simple in and out

Yep, unless I am missing something, it shouldn't make a difference.

 

[duncan2plus2]

It's just unnatural for engineers to cross hoses as shown in the FSM unless they had a good reason to do so.

 

[DrDmoney]

The inlet hose goes to the bottom like the FSM to help push the air out of the core.

 

[Flivver250]

If the coolant flows through the core in the wrong direction it will freeze your Jeep interior.

 

[Goatman]

Makes no difference as long as they let hot coolant into and out from the heater core. Unlike a radiator they are not designed to flow a certain way. That way the core can be installed in any way needed for a multiple of vehicle designs.

 

[duncan2plus2]

Good information...thanks.

 

[freedom_in_4low]

The inlet hose goes to the bottom like the FSM to help push the air out of the core.

For any heat exchanger, there are two reasons the flow direction matters.

The TJ heater core is a crossflow design, so it doesn't matter from a heat transfer standpoint. If it had multiple rows where water made one pass on the entering air side and a second pass on the leaving air side, you'd want the hottest water hitting the coldest air to maximize your mean temperature difference.

The other is to vent air. Air likes to go up, so if the water is going down it'll fight the air and you won't get full capacity. From that angle, I think it would matter.

 

[pagrey]

The other is to vent air. Air likes to go up, so if the water is going down it'll fight the air and you won't get full capacity. From that angle, I think it would matter.

That makes perfect sense, that's why the radiator flows from, wait a minute now, what are you trying to pull here?

 

[freedom_in_4low]

That makes perfect sense, that's why the radiator flows from, wait a minute now, what are you trying to pull here?

You don't think the location of the cap and overflow hose might play a role in venting air from the radiator?

 

[DrDmoney]

On mine the hoses are different diameters and lengths so they only go on one way, I thought they were all like that. Mine are just like the OP’s in fact same hoses, same color.