This how to guide is for WK1 model year 2008-2010 for the removal of the HVAC box. It can serve as a go by for 2005-2007 because there was a different dash and there for could possible be slightly different.
I needed to remove my HVAC box to fix my evaporator core that was leaking. It should be noted that because of the amount of work required to access the box the end user might want to consider replacing any parts showing signs of wear such as actuators, blend doors, blower fans, and gears.
2"-6" socket extension
T-25 Torque Screwdriver
T-20 Torque Screwdriver
Long handled pliers
small plastic container/bucket
Towels or rags
This should take about 1 hour to remove after the dash is already removed. Difficulty is moderate.
Set Ac controls to before removing from the Jeep. I recommend you set the controls to off, the temperature setting for the driver and passenger to the coldest or warmest setting. This way the vents will be fully open or closed as needed. Set the vent control in similar matter fully one way or the other. Doing this will help when you are reinstalling everything so you will not have any HVAC control problems.
Drain all A/c gas from the Jeep.
Remove the 1/2" bolt from the expansion valve located on the firewall above the passenger side of the motor. Use caution when moving the lines from the expansion valve. The smaller diameter one could bend if to much force is applied. There is enough play in both lines to move them out of the way to complete your work. It should be noted that the expansion valve is connected to the Evaporator Core and does not need to be removed at this time. If you want to you can but once the HVAC box is out it will be more easily accessible.
* When you disconnect your lines going to the expansion valve, there are O-rings that can fall off or will remain on the male end of the line. It is important you remove them so they do not fall off and become lost. I would recommend you replace them, when you reassemble the HVAC.
Here is a picture of the engine compartment. You can see the heater core lines going into the fire wall and just above that is the expansion valve with 2 aluminum lines going into it.
Using your pliers open the slide camps that are on your 2 heater core hoses. Again they are on the passenger side of the engine bay below the expansion valve. If you can get a funnel or small plastic container. When you pull the lines from the fire wall coolant will come pouring out. I would say 16oz came out but not more than.
Go to the inside of the cabin on the passenger side and you will see 2 aluminum pipes coming from the firewall to the front of the HVAC box. those lines are your heater core lines. Using your T-20 remove 2 screws that hold the lines to the HVAC box.
Place more of your towel and rags on the floor of the passenger side. Place your funnel under the connection where the heater core pipes meet the heater core and then place your plastic container under the funnel to catch more coolant. I am unsure of the amount that came out because when I did it it happened so face and there was some that spilled on my towels and on my Jeep's carpet. Now you can use your T-25 driver to remove the 1 screw holding the HVAC lines in place. Again use caution because coolant will come flowing out. Once it is out use a towel or rag to block the opening after the pipes are removed and carefully remove the Heater core. The heater core is removed because there will still be some coolant that will drain out. It is just a messy item that is better out of the jeep than in.
Go back to the engine compartment and remove the 2, 10mm bolts from the fire wall that hold the HVAC box in place. Once these two bolts are removed, the entire unite will be free and can be removed from the vehicle. Use the first picture as reference for the exact locations of the 2, 10mm bolts.
Your cabin of the jeep will look similar to this.
This completes the removal of the HVAC Box. The HVAC box can be opened. There are numerous T-15 torque screws that hold it all together. There are also some snap clips that need to be removed. Some of the actuators for the various doors will have to be removed to access all screws. Once apart the evaporator core can be removed easily.
The follow picture so the HVAC box open to show the evaporator core's location.
**I would also recommend that since you have everything all apart is to clean all your ducting that you can. There was dust that was easily wiped out. Also where the evaporator core is located, outside debris can get in as damage your core as it did mine. Remember the air intake for the HVAC is located on the passenger side of the firewall. Take the time to clean it out. I had dead bugs, dirt, and leaves in there. There is also a small drain hole that was partially blocked due to the debris.
Here is a picture of the old evaporator core.
To reassemble do the steps in reverse and take your time to make sure all the connections are done properly so you don't leak coolant or gas.