HCV Orientation and Flow
#31
#32
I have access to a factory original '99 XJ.
I will take a look at how the heater hoses are routed, and post back.
The smaller hose is usually the higher pressure hose, and the return hose is usually larger in most cooling systems....
Last edited by Firehawk068; 01-09-2015 at 08:17 AM.
#33
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Year: 1991
Model: Cherokee
Engine: 1999 4.0L
Smaller pipes flow faster than bigger pipes for the same units-per-second. The amount of fluid in the core at any given time is dictated by the unit-per-second flow rate.
Last edited by ehall; 01-09-2015 at 08:13 AM.
#34
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
What I am saying is the smaller tube on the bottom is the heater inlet!
You have it backwards.
The larger tube on top is the heater outlet.
The diagrams I posted are factory Jeep service diagrams, and they both show horizontal flow radiators?
I am not sure where you got your info from?
Maybe someone should start a poll.............Have people post how their factory hoses are routed.
You have it backwards.
The larger tube on top is the heater outlet.
The diagrams I posted are factory Jeep service diagrams, and they both show horizontal flow radiators?
I am not sure where you got your info from?
Maybe someone should start a poll.............Have people post how their factory hoses are routed.
The coolant flow diagrams u keep posting r WRONG (misprints)......They appear exactly like the coolant flow diagram in our '98 FSM......the coolant flow diagram in our '98 FSM is WRONG (a misprint) as well.
My information comes from what is logical.....the 3/4" (big) hose connects to the big 3/4" nipple on the core and the other end of the 3/4" hose attaches to the 3/4" nipple on the t-stat cover. Isn't it logical that since the 3/4" hose nipple is where coolant EXITS the motor (coolant bypass loop), that the other end of the 3/4" (big) hose would be the core INLET? Isn't it also logical (as stated several times now by others) that 5/8" hose would connect to 5/8" nipples and 3/4" hose would connect to 3/4" nipples?
#35
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
Forcing a 5/8" hose onto a 3/4" nipple is just asking for the hose to prematurely split, no?
I agree that we need some more '97 up and '96 down heater hose pics.
The pic in post #12 is after we did hose replacement using bulk 5/8" and 3/4" hose from the parts store. Here is a pic taken shortly after we bought the XJ showing the OE Factory hose routing. The routing of the hoses is different before/after (moved away from the valve cover for less heat transfer to the valve train) but what the hoses connect to and where the hoses connect is unchanged from OE Factory.
#36
I am saying the factory hose comes out of the top tube of the heater core(3/4), and steps down to 5/8 on it's return back to the water pump.
You cannot do this with universal bulk heater hose.
#37
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
If the heater cores r the same ('97 up & '96 down) then Chrysler/Jeep must have changed the coolant flow direction thru the heater core, but didn't change their diagrams.
Last edited by djb383; 01-09-2015 at 11:29 AM.
#38
I'll have info on a factory '99 later today.
#40
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Year: 1990
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I am going to trust Alan on this from his factory setup.
#41
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Year: 1990
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Engine: 4.0L
Just to confirm Alan (and everybody else)
This photo posted earlier is correct, though, right?? It matches what you said in your first reply with pictures of your setup.
Lower nipple at firewall is for 5/8" hose (smaller) and is fresh coolant going into heater core from t stat housing.
Upper nipple at firewall is for 3/4" hose (larger) and is return coolant going to water pump inlet tube.
This photo posted earlier is correct, though, right?? It matches what you said in your first reply with pictures of your setup.
Lower nipple at firewall is for 5/8" hose (smaller) and is fresh coolant going into heater core from t stat housing.
Upper nipple at firewall is for 3/4" hose (larger) and is return coolant going to water pump inlet tube.
#42
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Year: 1998
Model: Cherokee
Engine: 4.0L HO
Then the Factory reversed coolant flow thru the heater core with '97 XJ's but continues to show the old heater core flow pattern in '97 up FSMs.
Last edited by djb383; 01-09-2015 at 02:53 PM.
#45
Just to confirm Alan (and everybody else)
This photo posted earlier is correct, though, right?? It matches what you said in your first reply with pictures of your setup.
Lower nipple at firewall is for 5/8" hose (smaller) and is fresh coolant going into heater core from t stat housing.
Upper nipple at firewall is for 3/4" hose (larger) and is return coolant going to water pump inlet tube.
This photo posted earlier is correct, though, right?? It matches what you said in your first reply with pictures of your setup.
Lower nipple at firewall is for 5/8" hose (smaller) and is fresh coolant going into heater core from t stat housing.
Upper nipple at firewall is for 3/4" hose (larger) and is return coolant going to water pump inlet tube.
This is correct, based on how my '96 was put together at the Jeep factory, and by all the info I can find elsewhere.