Heater Core Replacement

[dragonsfyr]

Alrighty Then; My baby (Ghostie '88 Comanche)decided to dump the contents of her heater core on the floor. We have the new core. The question I have is........Wait for it.......Can the heater core be replaced without removing the dash. The reason I ask is that I had a ford once that said you had to remove the dash to replace the heater core and (I did it without removing the dash), also had a Chevy and a Dodge that I performed the same manual labor on (I hate removing the dash of any vehicle).

 

If it can't be done ....OK but if it can could I get an explanation of how (right now I can't find my Chilton's and it is getting kind of cold outside). I do not have AC. I already upgraded the cooling system to Open (yeah CSF Heavy Duty 3-core radiators are the BOMB I have a second one waiting to go into the '89 Cherokee).

 

I did use search and did not get any results that answered my question. So hopefully someone will have "all the right answers" :wrench: and I can get some heat back in my baby before it gets too cold and I end up riding the Motorcycle anyway.

[ratrapp]

i've done it without completely removing the dash out of the truck,but you still have to remove every bolt and screw anyway to loosen the dash up so you might as well take the dash out.

[Akula69]

I have never done it, but have studied it and decided it was easier to remove the whole dash, and then the AC/Heater case. I wanted to do this to not only replace the core, but to clean the case as well and replace the insulation inside (had mold and mice had chewed it). But, if you want to try, here goes:

 

If the AC/Heater case has never been opened, there will be a plastic strap (looks like a large zip tie) that is black in color running somewhat diagonal across the middle of the case. It is easily seen when you look up under the dash on the passenger side. You will need to cut this strap and remove the bolts (10 MM) near the seam this strap protects. You will not reuse or replace this strap.

 

Then, you will need to remove the 4 nuts on the firewall (11 MM) that hold the blower motor/ heater core section of the case in the truck. You will also need to disconnect the heater hoses from the core.

 

Finally when that half of the case is loose you will need to pry it apart and remove two bolts holding the core inside the case (8MM). Be careful not to bend the linkages for the blend air door. If you have large hands this step is almost impossible inside the truck.

 

Reinstallation is the reverse of those steps (except for the strap).

 

Good Luck!

[dragonsfyr]

Thanks for the input ....will try this later today.

[Automan2164]

Pull the dash. It's really not that hard in the MJ/XJ's. I could have it out in 15 minutes if I had all the tools next to me. Drop the column onto the seat, remove all the trim, pull the cluster and radio to disco the harnesses, and get the bolts that hold it under the kick panel.

 

I also did a heater core in a '97 Dodge Ram, now that was a pain in the butt. The MJ dash is nothing like that.

 

Rob :D

[dragonsfyr]

My aversion to pulling the dash has to do with the last time we had the dash out (that was to replace the wiring harness). My radio now blinks with my turn signals......... hmm (I have a little brother who is a ASE certified and he is the one that did it). SO pull the dash it is :wrench: :( . I should be able to get to that this weekend between homework, housework, work, kids appointments, and if it's nice I'm going for a motorcycle ride :clapping: .

[dragonsfyr]

That was an adventure in swearing..........Keman pulled most of the dash while I was getting the seats out (this was on Tuesday) then it started raining.....get the pop-up over the truck (more swearing) the instructions above were sort of accurate (I needed 7mm, 11mm, 5/16th wrenches) There were 5 nuts to remove from the outside of the firewall not 4 (two of which the studs came out with the nut, weeeeee). The heater core was NASTY as well as covered in oil. New heater core went in with new weather stripping and the swearing commenced on the re-installation of the dash, when it came time to put the instrument cluster back in we found out the speedometer cable was broken.

 

Wednesday; Got new speedometer cable, installed, swore a lot while getting the rest of the dash back in.........it is now back in the seats are re-installed and I have HEAT.......YEAH

[mvusse]

I think it is a crime for a heater core to be installed in such a way to make it easy to replace. I have done the front on my Suburban, which was almost impossible, and did the rear one twice. The factory installs the rear heater cores on 92 through 99 Suburbans before the rear glass goes in. THE ONLY WAY TO GET TO HALF THE SCREWS IS BY REMOVING THE REAR GLASS.

 

Be glad this was on a Comanche, as they are relatively painless compared to some other vehicles.

[AMCJeepMJ]

My GM H-body [LeSabre] requires the entire dash to be pulled to change a heater core. I took a look at one in the local salvage yard to see what it'll take to do it and its a major PITA. It is currently being used as a summer car [it has ice-cold air conditioning] and remains in the garage from September to May.

[dfreeman616]

i don't mind heater cores, one helped me nail down my current job :D i came in before i was hired and worked, there was a 2000-ish taurus with a heater core that needed to be replaced. it books out for 6 hours due to removing the dash, and the manager (another master tech) had done a few and knew about how long they take. when i started i asked if he had ordered the part yet, and he said he would get it for me before i needed it. an hour later i handed him the old one and he just stared at me like this :eek: and called me a freak of nature...and then ordered my part.

 

more on topic, i haven't done an xj/mj heater core yet, aside from pulling them from trucks i'm parting out.

[ratrapp]

i've done several heater cores in those year taurus's and they are alot easier than mj/xjs.you don't have to pull the heater box out and the dash doesn't have to be completely removed to pull a taurus heater core unlike the mj/xj.they're still a pain,just not as much as jeeps.