A/C Evaporator / Heater Core Replacement Writeup With Pictures

  • Posted on: 17 June 2016
  • By: xjnation

This writeup is for a Jeep Cherokee XJ 97-01.

Be smart and replace both the heater core and the AC evaporator even if one is not needed. I even did the blower motor as well. Doing all three adds a total of about 1 minute to the job. Do you really want to do this again in the future?

Take a lot of pictures when disassembling. It will be very helpful when you go to put everything back together. Especially if you are splitting the job up between a few days.

Time needed: Roughly 10 hours for first timer.

Tools needed:

  1. Phillips Screwdriver
  2. Flat Head Screwdriver
  3. AC/Fuel Line disconnect tools (can buy at any auto parts store for roughly $10
  4. Metric Socket Set
  5. Deep Impact Metric Socket Set
  6. Metric Wrench set
  7. Tape
  8. String
  9. Camera
  10. Stanley Knife / Razor Blade

The Writeup:

  1. Take one last look at your nicely assembled dash. 
  2. Make sure your jeep is in a place that it can sit for a couple days. This job took me 10 hours and since my jeep is from up north, everything is rusted so it took longer than usual to get some things off. Plan on this taking you two days.
  3. First step is to remove the charge from your AC System. You can either purchase an evac kit or have a licensed shop do it for you for a fee. Be responsible - please do not evacuate into the atmosphere.
  4. Disconnect negative battery cable and wait at least 20 minutes before messing with the dash. You don't want your airbags to go off in your face when disassembling.
  5. While waiting, either remove both front seats, or slide them as far back as they go. I chose to leave the seats in because the brackets were rusted solid and I wanted to save that fun job for another day.
  6. Carefully remove radio bezel by pulling outwards starting at the bottom by the shifter. (this is just held in by pressure tabs, be careful not to snap anything or you'll be making a trip to the local junkyard.)
  7. Remove the shift knob, shifter bezel, and boot if applicable and 4wd shifter bezel if applicable on the center console and remove the phillips screws (1 under 4wd bezel, 2 inside armrest compartment).
  8. Remove console. It helps if you shift into third gear (or neutral on auto) and pull handbrake all the way up in order to manuver the console off.
  9. Remove dash bracket and tape the bolts into the holes so you don't lose them or forget where they go. (two 13mm bolts)
  10. Remove the dash bezel and defroster trim and tape the screws in their holes. (Phillips screws)
  11. Remove the cluster (Phillips screws)
  12. Remove the plastic trim under the vent and the knee-blocker metal panel from under the steering wheel and tape the screws in their holes. (Phillips screws)
  13. Remove the bolts on the steering column so that you can rest the steering wheel on the driver's seat (if you left it in like I did) (2 14mm deep impact bolts)
  14. Remove the plastic trim panels below the door and over the hood release and tape all screws in their holes on the trim (phillips screws)
  15. Remove the 15mm bolts behind the panels you just removed that secure the dash in.
  16. Remove the 10mm bolts along the entire bottom of the windshield
  17. You should now be able to move the dash. Note: it will take a little muscle but don't overdo it. The dash is plastic and can break easily. Be careful when moving it. Pull the dash as far back as possible on the passenger side and let it rest on the seat (if you left it in) This will take quite a bit of trial and error but you'll get it back far enough eventually.
  18. Unplug the antenna by the fusebox under the passenger side dash area and unplug the temperature controls vaccum lines (shown in above pic)
  19. Disconnect your AC lines that go to the evaporator with your quick disconnect tool and tape a plastic bag over the end of your lines to make sure that nothing gets inside while you're working.  
  20. Disconnect the radiator hoses that go do the heater core and take a plastic bag over these as well. Note: some fluid will come out so put a bucket underneath to catch it if you don't want it on your garage floor.
  21. Unplug the black vaccum line that is coming from the heater core as well. It's just a small line.
  22. Now for the fun part: remove all five 11mm bolts on the firewall that hold the heater box in. The worst one is located just behind the valve cover and you will need to use a wrench to get it off. The rest can be done by using a deep impact 11mm socket. Tip: tie a string to your wrench and your wrist in case you drop it. If it slides on the top of the tranny bell housing, you'll need a new wrench lol.  Now, if the nuts are rusted on like mine, it will seem like the bolt is just spinning. Keep going anyways, the bolt is just threaded into the plastic heater box going the same direction (such a dumb design...thanks Chrysler) so it will unscrew from there and you will still be able to get the box out. Then you can just remove them properly when you have the box out and reattach them to the box.
  23. You can now remove the heater box from the inside.
  24. Move the heater box to a table or work bench and unbolt all of the 8mm bolts that hold it together. They should be pretty obvious, but there is one on the side that I missed initially. There are quite a few of these. 
  25. Slice the gasket where the box sections meet so that you can seperate them.
  26. Unscrew the blower motor and unplug it. Remove it before seperating the box.
  27. Take out the evaporator, and heater core and replace them with the new ones.
  28. Now put everything back together in the reverse order. The hardest part of the reassembly is lining up the screws on the heater box back in the holes on the firewall. If you can, find someone to help you. Doing this by myself took a good hour but I also had to deal with rusted bolts that would not come off and try to line them up with the holes on the back of the heater box lol. Not fun..
  29. This is where your pictures come in handy. Also, if you took my advice and taped the screws to the parts you removed, you will know exactly where everything goes. Saves you a lot of time! Everything will go back together a lot quicker than taking it apart.

Post your comments / questions below, and good luck!

 

 

Category: 
Cooling System
Air Conditioning / Heat
Time Taken: 
10 Hours