Heater Maintenance
12-12-2014, 06:07 PM
#17
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Year: 1990
Model: Cherokee (XJ)
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12-13-2014, 02:01 AM
#18
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Year: 1994
Model: Cherokee
Engine: 4.0
OK, ....so....what about having hot coolant in the heater core in the summer, when heat is the last thing you need in the cab ? Some of that must radiate in to the interior (??)
The PO replaced the HCV a week before I bought mine. I could toss it if there is no real heat getting inside of the cab with hot coolant in the core ...
It would be one less piece of plastic to fail...
The PO replaced the HCV a week before I bought mine. I could toss it if there is no real heat getting inside of the cab with hot coolant in the core ...
It would be one less piece of plastic to fail...
12-13-2014, 02:14 AM
#19
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Year: 1990
Model: Cherokee
Engine: 4.0
I don't bypass the control valves on my stuff, I make a point to move the heater control to hot regularly to flush the core, just like I run the A/C regularly during the winter to circulate the oil/freon through the system. Most systems run the A/C while in defrost so they get some during the winter but I do bypass those when possible, I generally don't need the A/C to defrost and rather not freeze in my vehicle longer than needed.
12-13-2014, 02:38 AM
#20
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I had that concern too and replaced the valve the first time it broke. That's some special extra-brittle plastic they used, after the second one broke I bypassed it. Didn't notice any difference in the summer, A/C on or off. I live in Wisconsin though, might be different in a hot state.
12-13-2014, 09:40 AM
#21
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Year: 1990
Model: Cherokee (XJ)
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OK, ....so....what about having hot coolant in the heater core in the summer, when heat is the last thing you need in the cab ? Some of that must radiate in to the interior (??)
The PO replaced the HCV a week before I bought mine. I could toss it if there is no real heat getting inside of the cab with hot coolant in the core ...
It would be one less piece of plastic to fail...
The PO replaced the HCV a week before I bought mine. I could toss it if there is no real heat getting inside of the cab with hot coolant in the core ...
It would be one less piece of plastic to fail...
I live in Arizona and do the HCV elimination on all my Jeeps. No issues.
12-13-2014, 10:11 AM
#22
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The HCV default position is "open" when the motor is off (no vacuum applied to the HCV). With the motor off and both heater hoses removed at the water pump and t-stat cover, a garden hose can be inserted in either heater hose to flush the heater core. When the temp selector ****/lever is moved from the full left (cold) position, vacuum is cut to the HCV, and it should fully open thus allowing coolant flow to/thru the heater core.
I would think during warm weather months it would be a good idea to turn/slide the temp selector ****/lever once a week or so (motor running) just to allow stagnant coolant in the heater core to be flushed out and replaced with fresh coolant. Remember, the HCV is controlled by the temp selector ****/lever, not the vent selector ****/lever.
No HCV.....no need to move the temp selector ****/lever.
I would think during warm weather months it would be a good idea to turn/slide the temp selector ****/lever once a week or so (motor running) just to allow stagnant coolant in the heater core to be flushed out and replaced with fresh coolant. Remember, the HCV is controlled by the temp selector ****/lever, not the vent selector ****/lever.
No HCV.....no need to move the temp selector ****/lever.
12-13-2014, 10:15 AM
#23
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Yeah. I'm stealing it!
12-13-2014, 11:29 AM
#25
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Yep, that's why I stated "*****/levers" and "turn/slide".......levers for the oldies but goodies and ***** for the newbies.
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