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

390466 Views 482 Replies 156 Participants Last post by  cyintherye
10
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. Anyway....here'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 side....it'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.

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.

TO BE CONTINUED...
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thanks so much for a great write up and for so many helpful pics. I just started tearing apart my XJ today to replace the heater core, but at the advice of the commerical parts supply house, I'll also be replacing the evap core at the same time. After seeing the pics, it looks like the blower motor is only accessable when the HVAC box is out, so I'll replace that part as well.

I don't have a FSM, so my plan was to just use my VW experience and just figure things out as I go along. ( VW's from 1993 to present also require the full dash to be removed for heater core replacement). I wouldn't have thought about removing the seats, but now I see what a good idea it is.

I hope other people will find your write up as useful as I have.:thumbsup:
Does the whole dash need to come out for pre 97's? That is one crazy design. I can see now why I've heard shops quoting upwards of 1000 bucks for this job.
Why did you change the accumulator? Was there something wrong with it, should it be changed for some reason? And lastly if you change both you said to put in 6 oz total of oil? My A/C leak too and they say it's the Evap. but I have yet to work up the will/care/decide to start doing something about it.
The blower motor can come out/be changed without having to do any of the dash removal or anything. The accumulator was replaced just because. I had the system open to the elements for about a week so the dessicant bag in the accumulator was probly shot anyway.
Why did you change the accumulator? Was there something wrong with it, should it be changed for some reason? And lastly if you change both you said to put in 6 oz total of oil? My A/C leak too and they say it's the Evap. but I have yet to work up the will/care/decide to start doing something about it.
it's considered wise practice to replace the accumulator (with it's dessicant) any time you have the system opened up for long periods such as when replacing major components.
I'm convinced my A/C hates me.....after all that this summer, I finally got the heater core changed back out and everything buttoned back up, A/C charged and boy did it ever blow nice and cold.....for about three days then my condenser packed it in......back to square 1....I left it though cuz it was September and I couldn't justify spending MORE money on A/C at that time of year.....it'll wait until the spring
Unfortunately this is way out of my league. My regular Jeep mech doesn't even do them, takes them to a referral shop.
What would be a fair price to pay?
I'm in Denver.

Trying a flush with additives and refill but not holding out too much hope. 130,000 miles 2001 Jeep Cherokee Sport 4 liter. Blows cold air until about 30 minutes go by then luke warm on low setting. Enough to keep it above freezing for now, but planning ahead, don't know if I'll make it through Winter. Storm chasing skier to make matters worse.

Thanks
fyi, I had good luck with the solvent. Let it run for 150 miles over 3 days. Backflushed the heater core from both sides. Large difference before and after, both in temperature of the hoses and the air in the cabin. Absolutely recommend it for anyone who has a slowly clogging core.

I don't expect it to last forever though, hope it gets me through the Winter. So still curious what a fair price is.
Does the whole dash need to come out for pre 97's?
I'd like to know the answer to this one as well. Does anyone know? I'm in the market for an XJ, and if the 96 and earlier were easier to put a heater core in, it may influence my decision.....
I'd like to know the answer to this one as well. Does anyone know? I'm in the market for an XJ, and if the 96 and earlier were easier to put a heater core in, it may influence my decision.....
The Pre-97 heater core R&R procedure is pretty much the same as that for the later models.
also, when taking out the bolts along the top of the firewall that hold that dash in- be very careful- they have a very shallow head and the ratchet might slip off and smack your windshield. and put not one but two cracks in it, in a perfect crosshair fashion. :rantscream::thumbdown:
just did the heater core exploration/deconstruction/reconstruction process and this thread was used during the whole process. Thank you for making this for everyone and thanks again from me. And I did not pull the steering column, but kinda wish i did as it probably would have been easier putting the hvac box back in.

thanks, chris.
my buddy and i just replaced the heater core in my jeep, and we ran into the same problem. put everything back together, and then it leaked, so we took it all apart again and had to get a new core. the first time we took everything apart, but the second go around, we left the steering column and just unscrew the dash and were still able to get the hvac unit out. it was a lot easier the second time :laugh: but i hope to never do it again.
HVAC foam seals

I am replacing the heater core and the evap on my 98 wrangler sahara. I contacted a local dealership about the foam seals around the evap/heater tube. They told me they could not find them, I was wondering if anyone had part numbers or could send me a link to purchase them online. Any help would be greatly appreciated. :confused:
I just did it and with your instructions and pics it was easier than i thought.
Thanx! :thumbsup:

I didn't remove the steering wheel from the column. I removed the whole column. The 2 shafts just slip together near the steering box. That avoids removing the airbag and using a puller on the steering wheel.

AutoZone has that spring lock tool for disconnecting the refrig lines for $10. When you reassemble the lines, make sure you push them together so they lock, then put the clip on. Napa has a seal kit which includes new springs.

All from Napa in Mechanicsburg, PA:
Evaporator- $125.
Heater core- $70.
Refrig line seal kit- $10.
Accumulator- $40.
I'm getting everything to replace my evap and heater core on my '01 XJ. Having trouble finding suppliers for the foam and seals you replaced... any direction would be greatly appreciated.
I'm getting everything to replace my evap and heater core on my '01 XJ. Having trouble finding suppliers for the foam and seals you replaced... any direction would be greatly appreciated.
The dealer has a foam/seal/insulation kit for the heater core.

Auto parts stores have the o-rings for the AC lines.
geez.....i got upset today when i found out how much it was going to cost to fix, and now that i know what all has to be done to fix it, i almost want to pay 900 dollars to have it done :thumbdown:
Awesome Write-Up...I'm getting ready to tackle this beast with Manual in Hand.
Excellent write up, but seeing this just makes me think paying for this repair to be done at a shop would be worthwhile...what a job!
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