Evaporator Core Change

[Sneedle Vision]

Alright, here's the deal. AC has been flushed and dye twice to find a leak, no such luck. The shop that did it said it's probably the evaporator core.

I know it's a pain to get to, but apart from that, is this pretty straightforward?

I read the heater core might as well be changed while you're in there, but I'm more curious about the ticky tack stuff. Any info provided will help. Not really wanting to sink $1000-1500.

[4.3LXJ]

You have to remove the dash. That is the rub. You will only have to get it loose and up on the passenger side to do this. And yes, replace the heater core while you are there.

[Sneedle Vision]

You have to remove the dash. That is the rub. You will only have to get it loose and up on the passenger side to do this. And yes, replace the heater core while you are there.

Are there any specialty parts that are required to replace in addition to these? Tips?

ie: If i had to do it again, I'd make sure to do _____, _____, & ______.

[4.3LXJ]

No, not really. General hand tools work

[Sneedle Vision]

In one of the guides I found, it said to put put 2oz of refrigerant oil in evap core when installing. Does this sound right? Can I literally pour the oil in the inlet side?

I'm sure this sounds silly, but I want to make sure not to screw it up.

[4.3LXJ]

Not sure what AC pump you have, but if you have one like the one on our WJ you can pull the plug on the top and put it into the compressor too. But yes, you need to replace some of the oil you lost and that method is one way

[jimmixj]

Usually if the evap core is leaking you can spot the dye at the drain port, but not always. It is a round tube about 5/8 to 3/4 inch located below the emissions can on passenger side of engine bay. That said, replacing the evap core is time-consuming and scary but not that difficult. I've tried to "cheat" by just lifting the dash but found it is easier to just remove the whole deal. There are only a few bolts that hold the whole thing in place. Just be methodical and take your time. If you want a step by step I can provide one. These pics are of the last one I did.

[Sneedle Vision]

Okay, well day 1 of evap core change is in the books.

It was pretty straightforward. We were lucky enough to find a copy of the FSM online, so any questions regarding order were easily handled. The absolute worst part was getting the bolts that actually hold the HVAC box to the firewall. The only other issue was regarding someone rounding a bolt.

But the new cores are in, and bolting everything up and making sure everything is back in order begins tomorrow!

Looks like the Jeep gods looked down on us in favor today! :bacondance:

[Sneedle Vision]

We've hit a tiny bit of a snag.

Everything bolted in right and we made sure there was no connector left unsecured.

But... when we started the Jeep, and turned the selector for Recirc, Floor, Defrost, the air never changed to other vents. The knob doesn't seem to turn the same way anymore either, it felt as if it was a little pressurized before so there was a positive reaction to turning the knob. (One positive is that the heater core worked well, cause the air was super hot when we changed the temperature dial!)

We've double checked all the vacuum lines and things seem to be snug and in place.

When we initially unplugged the entire AC control panel, the plug for that switch, it gave off a sound of the seal breaking with a slight "pffffsst" sound. (if that makes sense).

Any thoughts?

[4.3LXJ]

Pfffft, was vacuum left in the system. It means it is working well. Get it plugged back in good enough?

[Sneedle Vision]

Pfffft, was vacuum left in the system. It means it is working well. Get it plugged back in good enough?

Yeah, luckily enough, we were able to pull the same switch out of my Dad's 99 XJ and try it in my XJ. And BOOYAH! It worked, it pushed the air through all the proper ducts.

So apparently, however we disconnected it the first time completely put it out of whack. Cause when we put the original switch back in it's original place, it still was broken.

So it looks like I'll be searching for a replacement switch housing. But that's not that bad.

[4.3LXJ]

Nice to have spare parts eh?

[Sneedle Vision]

Since we screwed up the AC control switch, we had to get a replacment. There weren't any locally that we were able to test to make sure worked properly.

So ended up going to Davey's Jeeps and they shipped one that was guaranteed for $35. Got it from Ohio to NC in 2 days. Worked like a champ! Can't say enough good things about them.

Once it was in, went and got the system recharged and it's holding the cool! The techs that checked out the Jeep were impressed at our work with the evap core!

With the cost of parts and inital diagnosis of the AC system, we saved $800!