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A/C Evaporator/Heater Core Replacement - How-To:

xjguy98

NAXJA Forum User
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

IMG_0343.jpg


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.

IMG_0344.jpg


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. Anyway....here's how to remove the column if you're so inclined.
16) I removed the airbag...don't know why...

IMG_0348.jpg


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

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19) And upper shroud

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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

IMG_0351.jpg


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

IMG_0353.jpg


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:

IMG_0355.jpg


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

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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 side....it's a mess but it looks worse than it actually was.

IMG_0356.jpg


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.

1) MAKE SURE IF YOU HAVE REFRIGERANT THAT IT'S EVACUATED BY A PROPER SHOP. DON'T OPEN LINES AND LET IT ESCAPE....IT'S AGAINST THE LAW AND BAD FOR THE ENVIRONMENT. There I said it...
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.

IMG_0359.jpg


Here you can see bags over both the accumulator and liquid lines.

3) I was replacing the accumulator as well so after I disconnected it, I removed the old one and transferred the low pressure switch over to the new one.
4) Disconnect both heater hoses from the heater core (using a bucket to catch the drips) I couldn't get mine removed so I disconnected them from the other end, fed them through the firewall and reconnected them to the engine afterwards.

IMG_0360.jpg
 
You went a bit further than I did with mine. I took everything apart just enough to get the passenger side of the dash to swing out far enough to let the evaporator unit come out the bottom. Surely someone would figure this out, but you might add something about the five? studs that hold the evap unit to the firewall. The one behind the engine on the bottom of the box gave me some problems because the stud was bent over. Good write up and pictures. :cheers:
 
XJguy98 --

Did you need any special tools to remove the connections to the evaporator?
I'm gonna do this job next weekend.

Thanks

You need to get a set of the spring release tools. Uses the 5/8" and 3/4". Got these http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=98118 from Harbor Freight. They worked pretty good. Just did mine last weekend. Do yourself a favor and get new orings and springs for the connections. I now have A/C in my XJ just in time for the Hot Humid Houston summer.
 
For those attempting this job -
get yourself the spring clip removal tool (buy a metal one, the plastic one will most likely break like mine did)

also buy new hoses for your heater core, as those are probably melted/fused to the pipes.

It's not a bad job, took me the majority of a day with good results.

Would I do it again? Sure thing!

I bought all my parts from http://www.jeepair.com/
The guy new every detail of what I needed.
He also said to use PAG 46, not 100 weight.

4 0z. into the evaporator before installation.
 
Just did mine last weekend. Steering wheel must come out but column can stay and just slide the dash over it.
 
Just did mine last weekend. Steering wheel must come out but column can stay and just slide the dash over it.

When doing it this method, you'll have to remove the turn signal and wiper switches to get the dash to clear, but it comes out pretty easily.
 
So is it worth doing this or should I just take my Jeep to a shop. My Evaporator Core has a leak.
 
It depends on how much you think your time is worth. I started my project on a Friday evening, and had cold air by Saturday afternoon. A couple of things slowed me down (lost a nut or two that took time to recover) and I tried to be slow and methodical.

So maybe 10 hours of my time. Two local shops (1 dealership and 1 independent) quoted anywhere frmo $800-$1100 (estimated 8-10 hours shop time). My evaporator core costs about $150 from NAPA and I maybe spent $50 total on freon. So to me it was worth it. I still haven't had the system evac and charged by a professional, which is breaking all of the rules, but it still works over the last two summers.

I'd do it the same way again rather than spend the grand to have some one else do it. Maybe I'd have it professionally charged), but that would still put my total to something like $350 vs. $800 (minimum). I figure I could have paid myself $50/hour. I'm fine with that wage for a weekend.
 
Wow this thread is great and informative! Thanks.

Sorry to bring this thread back to life but I was unable to find a similar writeup for the '96 and earlier XJ's. If anyone knows has a link for one I would sure appreciate it as I'm 99% sure my evaporator is leaking.
 
Wow this thread is great and informative! Thanks.

Sorry to bring this thread back to life but I was unable to find a similar writeup for the '96 and earlier XJ's. If anyone knows has a link for one I would sure appreciate it as I'm 99% sure my evaporator is leaking.

The 96- isn't the same, but shares some of the same steps.

It has the same pivot bolts.

It has the same upper dash bolts(you need to remove a trim/vent piece to get to them).

I removed the steering column on my 88, which made it pretty easy.

The HVAC boxes share the same in engine bay nuts that need to be undone.

Sorry don't know of any thread, but theres a few tidbits for you.
 
This is a great thread for sure! I am hopeful someone will post a write-up/pics for thos of use with 96 and older XJ's. Nonetheless, this helps greatly! Thank you all for the great information.
 
seeing this thread makes me glad my XJ is no longer a daily driver and just used for summer play. if/when the heater core develops a leak, it is just getting bypassed in the engine bay.

Nice write up :yelclap:
 
OK guys, I need a answer on this. Is there anyway to just change out the heatercore without unhooking the AC?

I really need a answer fast due to the fact this is a DD now and I am at the point were I have the dash pulled but still have the Hav box still in place.
 
I'm doing this over the holidays. What are the odds that we can get the pictures back up an running. Anyone in contact with the OP? Thanks!
 
I'm doing this over the holidays. What are the odds that we can get the pictures back up an running. Anyone in contact with the OP? Thanks!

X2 on that one! I have a crack in the housing and I'm dreading repairing it. This write up along with pictures would be greatly helpful!
 
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