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My ACTUAL Evaporator/Heater Core Removal/Installation Thread.....

390412 Views 482 Replies 156 Participants Last post by  cyintherye
Seeing as how this is a pretty common snag with our Jeeps, I figured I'd add to the list write-ups on how to do it. Lots of pics so sit back and read on

The first thing I did was disconnect the negative battery terminal. A) because you'll have your doors open and courtesy lights on for a LONG time and B) so your airbags don't go off when you're in the middle of removing the dash.......don't be lazy...DO THIS NOW. After that and while you're waiting for the capacitors to discharge and for your airbags to be safe, go ahead and start removing the following:

1) Both front seats (makes access to everything much easier)
2) Both lower a-pillar trim panels (or kick panels, whatever you call them)
3) The lower steering column cover/metal knee blocker

4) Remove the center bezel that covers up your stereo/heater controls/switch panel
5) Remove your headlamp knob by reaching up and pressing the release button on the inboard side of the headlamp switch. The knob should just slide out.
6) If you have tilt steering, set it to the lowest position and disconnect the rubber steering column surround.
7) Remove the instrument cluster bezel (held in by snaps and four screws)
8) Pry the rear edge of the top cover up to disengage the seven snaps.
9) Once clear, pull the entire top cover rearward and disengage the remaining four snaps.
10) Remove your shift knob (it helps if it's in 1-2, sit in the back seat, brace yourself and give it a good pull and it should come off. Don't punch yourself in the face while doing this)
11) Remove the shifter and transfer case bezels and unplug the light bulbs.
12) At this point, you can remove the two screws holding the front of the center console down. Open the console and remove the remaining two screws and the console should be able to be removed. It might take a bit of finessing to get around the parking brake handle though so be careful.
13) Pull the carpet (if you have carpet) back far enough so you can see the two lower nuts holding the panel center support bracket to the tranny tunnel.

14) Remove the two lower nuts and the two upper nuts and remove the bracket from the vehicle.
15) At this point in the FSM, it tells you to remove the steering column. From everything I've read, you don't HAVE to but I did. It was a pain and the next time I do this, I'll unbolt it from the bracket but I'll leave it in. You only need to be able to swing the dash out enough to access and remove the HVAC box from the firewall.'s how to remove the column if you're so inclined.
16) I removed the airbag...don't know why...

17) You can pull the steering wheel off the column. I didn't because one of the holes for the puller was stripped so I left it.
18) Remove the lower shroud

19) And upper shroud

20) Unbolt the steering column coupler bolt from the intermediate shaft. You may need to turn the wheel in order to access it.
21) Disconnect all the electrical connectors associated with the steering column as well as the brake park interlock switch from the ignition cylinder. I removed the ignition cylinder as well but you may not need to. The interlock switch just clips in to the righthand side and drops away.
22) Remove the two vertical mounting nuts and the two horizontal mounting nuts from the steering column and support it as you lower it off the bracket. You can now pull the column out of the dash. Here's the dash with the column removed, the wiring harness on the left and the interlock switch and solenoid on the right

Here's a view of the mounting studs and coupler for the steering column:

23) Remove the bolts from and disconnect the two big electrical connectors under the lefthand side of the dash. The rearmost one should be the gray one and the forward one should be the white one. I had trouble with the white on and left it hooked up so I couldn't COMPLETELY remove the dash. No pics of these because I was pissed off
24) Just to the left of the tunnel and under the dash as well is another big grey electrical connector. Remove the bolt and disconnect this, as well as the small yellow airbag connector that should be around the middle of the under-dash area.
25) At this point, you can switch sides and roll down the glove box. There's two rubber stoppers and if you remove them, the glove box will rotate clear allowing you to gain access to the rear of the HVAC box.
26) On the lefthand side of the glovebox opening, you should see the white vacuum connector. Disconnect the two halves. Also, you should see a big green connector for the blower motor. Disconnect this as well.
27) Reach under the righthand side by the fuse panel and disconnect the two halves of the antenna cable.
28) You can go two different ways with this next step. I tried the by-th-book method and it didn't work so I improvised. The book says the remove the temperature control cable from the HVAC box by unscrewing the blend-air door bellcrank from the door shaft underneath the dash. I couldn't get it unscrewed so I removed the heater control panel, separated the cable from the control head and routed it clear of the dash itself so it hung clear and out of the way. You can do whatever is easiest for you.
29) Loosen the left and right dash roll-down screws about 1/4" They're located right next to each courtesy lamp so they're easy to find.
30) Remove the four bolts that secure the upper-forward edge of the dash to the firewall. There are two on the left and two on the right.
31) After the bolts are out, remove the two nuts (upper forward edge) holding the center of the dash to the firewall. The dash won't fall away with these removed as the studs are still holding it in.
32) With some help (I did it alone and it was a struggle for me) lift the dash up off the two center studs and then pull it backwards to clear the roll-down bolts. Your dash area should now (hopefully) resemble this:

At the left of the picture above, you can see one of the big gray body connectors.

At the center of the above picture, you can see the temp control cable, as well as the green blower motor connector and the vacuum connector.

With my dash swung out of the way due to that stubborn connector on the lefthand's a mess but it looks worse than it actually was.

NOW, hopefully nothing was left connected and your dash should be out of the vehicle. If you forgot anything (or I forgot to mention anything) now's the time to disconnect or remove it. I found that bagging and labelling EVERYTHING (no matter how small) REALLY helped when I put everything back together. Grab a box for the parts bags and set aside a small corner for the bigger parts. The more organized you are, the easier the job will go for you because it's easy to misplace/lose things.

Anyways....on with the HVAC box. The FSM says to drain the coolant but you don't need to. Just make sure you have a small bucket or tupperware container to catch the small amount of fluid that will drain from the heater hoses as you disconnect them from the heater core.

2) Using an A/C line disconnect tool (I paid $14 for my set at the parts store) disconnect the liquid line from the evaporator inlet and the accumulator from the evaporator outlet. Mine have never been done so they took about 20 minutes for both but they came out. Make sure you cover the lines somehow. I used a couple of bags with zip ties to keep crud out. The less contamination the better.

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Hello All, Brand new to this form, I came here looking for information on replacement of both the heater and AC evaporator cores. I have had my 1999 XJ limited for the last seven years, heater core has leaked a little the past 3 years and this summer it started leaking more so I disconnected it.

I ran across this 11 year running thread and have been reading much of it and will be starting to tear down my dash for replacement of the cores next week.

I've visited my local radiator shop where I was told they may be able to repair my existing copper heater core, if repair is not an option they may be able to recore my unit using my endcaps and it would be like new. The final option is buy an aftermarket aluminum heater core but it appears from reading post on several sights they quality is spotty and I could end up doing replacement again in a few months or few year

A/C Evaporator Cores. It appears these last longer then the heater cores?

With so much history on this thread I wanted to ask those that have replaced there heater and A/C Evaporator Cores, what brands they used and how many years they have been in trouble free operation.
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Amazing instructions, thank you! Love the comments, all. I'm a new member with a heat-bucket of an xj this summer until I can get this repair done! Thanks also for the working post of the PDF.
This is my experience from what I learned reading this entire thread....
Wow, amazing summary, and incredibly helpful labeled photo, many thanks!
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