Jeep CJ Heater Core Replacement

CJM1971

Member
Joined
Jan 24, 2017
Location
Raleigh, NC
Morning, any forum viewers have any helpful info on replacing a heater core? Found a small puddle of coolant on the passenger side floor. I dont believe the heating system actually works and I dont need heat so is it ok to remove the core and leave it out assuming there is a hose or two I will need to plug that carrys the coolant? This is just a weekend driver so heat, air, and defrost arent necessary.
 
First question is, does you Jeep have AC? If so you will need to remove the 4 bolts that hold it in place and let it hang. After that you will need to remove the glove box. Then remove the cable connections to the heater box. If memory serves me there are 4 nuts on the firewall, one behind the engine head, one easily accessed, and 2 under the battery. You don't have to take the battery out but it does give easy access to the bolts and a good chance to clean all that up. once the 2 hoses are removed you can work the entire heater box out, don't forget to remove the fan wires, etc. Once out and on the bench there are a few thousand screws holding the plate in place. The blower motor comes off first and you will need to make sure you put it back in the exact orientation or it will not go back in correct. Pay attention to the flaps and make sure your flap "pins" fit into the cover or your heater will not work correctly. Not a difficult job but you will need to pay attention to how it comes apart. I think your biggest worry will be rusty bolts as the heater box is fiberglass/plastic and you could run the risk of turning the studs off in the housing. Would suggest spraying the nuts liberally with penetration oil between now an the weekend.

Good Luck!!
 
Thanks for the reply, I will have to check as to whether or not it has AC, but as soon as I saw that drip of coolent from underneath the box on the passenger side I new right away that it was something to do with that system and I didn't want to mess with it. This leak isn't bad but I am just not ready to dive into all that at the moment but it looks like I'll have to. Fan switch doesn't work, not even sure all the cables are hooked up for it even to work if I didn replace the fan switch, so I was hoping to just remove the core to stop the leak instead of throwing money to replace parts on a system that doesn't work anyway if that makes sense. Is there a way to just plug the hose carrying coolent to the system and stop the leak so I don't have to remove the system or does the coolont for the whole vehicle cycle through this system as part of the overall travel.
 
I really just want to stop the leak and call it a day, this is a weekend driver to have fun in with my 7 year old and the wife, this jeep has been modified over the years and it doesn't look like all the items were set back up like they were when it was all original. When the fiberglass body went on I'm not sure the original owner, a couple of owners ago, hooked everyting back up.
 
Thank you, I believe I saw that last night, but Im struggling with taking it all apart when I dont need it nor will I ever and just bypassing it or fit it now. I already know the whole heating unit, ducts and all, arent all there so there is my struggle to fix it, it will never be a show jeep and it will always be in the garage. Guess if I bypass the heating unit I was told to run a straight loop. Took a look under the hood by the battery holder, looks to be 2 hoses side by side right about where the core is. Looks like one goes to the water pump and the other to the back side, up top, on the engine block. Any clue if thats where I run a staight loop of hose, from thr block to the water pump? I have a pic if that will help.
 
IMG_0387.JPG
 
Not a great pic but enough to see the 2 hoses side by side at the firewall. Black one goes to the water pump and the read ine to the back of the motor up top
 
CJM1971 said:
Not a great pic but enough to see the 2 hoses side by side at the firewall. Black one goes to the water pump and the read ine to the back of the motor up top
Click to expand...
Yep, that's it. Just yank/cut em off at the firewall, & couple together. Or plug both off. I don't know of any reason you Have to loop them. Plus their suppose to be different sizes, though some get away with using 1 size hose.
 
I've done emergency roadside heater core bypass, by looping the inlet back to the outlet. Worked fine, except it was winter, we were on our way to ski at snowshoe, and we froze our arses off.
 
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