The most common leak point of the Cherokee A/C system is the Evap Coil. If you access the Evap Coil by removing the entire dashboard and heater box, you might as well replace it and the heater core too.

http://www.jeepforum.com/forum/f11/my-actual-evaporator-heater-core-removal-592844

 

I think i might actually attempt this if the pictures were still there.

 

Wow. That's one helluva write-up! I sincerely appreciate it!

My only question is, if there are so many problems with the Evap Core, why?

 

Yep, just had my evaporator and heater core (cause they were there and it is 11 yrs old..echo what CJ7 Tim states) replaced yesterday. The original evaporator went out when it was only 3-4 years old, repared under original warranty. The second one leaked a little bit over the last 4-5 years, till last fall when it wouldn't hold anything.

Why?? My understanding the Chrysler 134a evaporators from the mid 90s to early 2000s are junk, thin tin-foil like in design, vs the thicker R-12 cores used in earlier years. It is annoying to say the least that if you are not skilled in AC work or comfortable pulling your dash apart you have to dole out so much cash on a creature comfort. Too hot here in St. Louis during the summer not to have it, hopefully the aftermarket unit will do better than the two Chrysler units.

 

If you want to be CERTAIN it's the evaporator (and the odds are heavily in favor that it is), use a "SNIFFER" instead of a dye for leak detection.

 

Anyone have any preference/good results on where to buy the Evap/Accumulator/Heater Core from? I don't want to do this again...... EVER.

 

I bought mine at NAPA

 

Well, I did my evaporator coil over the weekend and 4 days later, I believe I have correctly solved the issue. It was one heck of a job, but living in Florida, A/C is a must.

I believe I did it on the last "cool" weekend of the year too, as this week temps are already in the high 70's, low 80's.

I bought all of my parts from Advance Auto Parts due to their extensive coupon codes (saved a ton of $$) except the heater core, as I saw a few bad reviews on the one they sell. I bought the heater core from Napa and it fit perfectly as designed. (I replaced it as I didn't want to ever pull the dash apart this decade again)

I bought a Vacuum pump from Harbor Freight a few months ago on sale for $50 dollars, which in my mind, was a steal! It pulled the required 30in/Hg and vacuumed the system down.

During the install, I replaced the O-Rings, Accumulator, and Schraeder valves to alleviate any issues as well, as a can of R-134a is now $14!!!!! When did the price of R134a Double/Triple?!?!

Also during the install, since the system was apart and changing out pieces, according to the factory manual (when changing out evaps, compressors, accumulator, etc you have to re-add more oil) I added the 3.5-4oz of PAG100 oil that had the UV dye in the oil. This was the best option (to me) as it didn't appear that I would be diluting the system with just dye. This way, if I ever have a leak in the future, it will be BRIGHT UV!!! I was able to purchase the oil/dye mix at Napa as well.

Everything is blowing ICE cold and I've been driving it to work all week, and by now, the coolant would have leaked out or been causing the compressor to cycle. It was a relatively clean job and my dad even helped and kept me sane during this endeavor. I estimate it took about 12-13 hours, part of that was just figuring all the connections to dissasemble, etc. We ended up taking the entire dash out (pulled the steering column, wasn't that hard) for ease and to ensure I didn't break anything. I have a XJ limited and my interior is the still MINT as the previous owner didn't trash it.

Any questions, just ask. It's still fresh in my mind from the weekend.

 

I have been chasing a leak in my A/C system for quite some time now and the only piece of the system I have yet to definitely write off the list is the evaporator coil, as I really cannot see it....

My testing procedure has been the following:

1. Fill the system entirely with R134a w/ UV dye
2. Run the system over several weeks examining the system at night with a UV light.
3. Over a period of a month, I have put 3 cans of R134a w/ UV dye in, and I have yet to see any leaks at all! I have examined every line, connection, compressor, condensor, etc under the hood, but the evaporator I have yet to check out.

My question is this, has anyone removed their Evaporator Coil? It sounds like a PITA, and I was wondering if anyone has any more tips/tricks before I waste my time or find out that the Evap coil is not an issue.

Thanks in advance. :thumbsup:

Sorry, that IS the issue. I read about it on here when I bought mine and discovered it had no AC. I had the system tested at an AC shop and they said it leaked no where under the hood and that it was probably the evap coil under the dash. So, one evap and a couple cursing-filled days later, I had a leak free system.

Make sure that if you do this repair, you have the AC correctly recharged using a machine that pulls a vacuum on the system before it charges it with R134A. Using those little cans of R134a on a system with no pressure will make it so it wont ever take the full amount of refrigerant, subsequently making it so that your AC never runs at its full potential.

 

I know this is a few months old but Im in the same dam boat now. Just replaced everything in the system and its leaking somewhere! My only guess is the evaporator but I have another cherokee with 30k miles I use as a parts truck so it has a free core for me. Where exactly was it leaking from so I can attempt to prevent it from happening again! If you have any pics or can tell what you guys find is the common spot/s that leak it would be a HUGE help to me. I have a trip to FL this coming monday/tuesday so I must have AC for this trip to the Keys!

Thanks

 

I know this is a few months old but Im in the same dam boat now. Just replaced everything in the system and its leaking somewhere! My only guess is the evaporator but I have another cherokee with 30k miles I use as a parts truck so it has a free core for me. Where exactly was it leaking from so I can attempt to prevent it from happening again! If you have any pics or can tell what you guys find is the common spot/s that leak it would be a HUGE help to me. I have a trip to FL this coming monday/tuesday so I must have AC for this trip to the Keys!

Thanks

Unfortunately, 97+ OEM evaporators are very poorly made, and prone to developing leaks. Most of them seem to leak in the dip-brazed joints between the tubes, and the only way to spot the leak is to look for an oily spot, but even THAT is not proof positive.

If I were going to all the trouble of replacing my evaporator, I would NOT use one from a junkyard vehicle. Since they are known to be prone to leaks, you might put in one that may leak now, or may leak very soon thereafter.

Buy an NEW evaporator, preferably from some source other than OEM.

 

Im sure you have done this already, but I was lucky and when I inspected the box under the glove box closely with a bright light. I saw a small gash, couldn't even see if there was a hole or not. I put some jb water weld putty in there to cover the gash with very slim hopes that my jeep would stop leaking water from under the dash everytime i ran the ac. I let the putty dry for about 1 hour and came back to test it and it hasn't leaked since. cant hardly beleive something so small could cause such a huge leak and that i didnt care to fix it for 2 years of nagging. :kiss:

 

What I did to test was I charged the system and put UV dye in before I did; I ran the system for a week until it all leaked out again, and while this was going on, I used a UV light I purchased off Amazon (saved me about 15 bucks) and never saw anything!

So I figured it had to be the evaporator as I have heard all the comments about the poorly made late 90's-early 00's evap issues.

When I took the dash apart and the HVAC box, sure enough the Evap was all coroded at the bottom, with a light hint of UV dye. (Not sure if the water condesing on it washes it away)

+1 on not using a junkyard Evap Core; it took me a day, my Dad was along to keep me company, and I replaced my heater core while I was in there as well. (Replaced the Reciever/Dryer too) I bought a harbor freight vacuum pump and pumped the system down and let it sit for an hour to check for leaks. Maintained a vacuum perfectly. Charged it up and system blows Icicles now! Take your time, do it right, and save about $2,000 from what the dealer wants; you'll be proud of yourself...

It's not a complicated job, just a tedious, long one.

 

awesome

 

Yes Im in the process of taking it apart now. I have a 2001 Jeep with only 30k miles thats my "parts truck" but I'm deff going to order the NAPA core and you guys think its safe to use the heater core from my parts truck? Again only 30k miles on this truck.

 

If it were me, if I were going through all that labor I would put a new one in vs what you have there. Let us know how it goes!

 

:thumbsup:

 

Yea my only issue is I cant get one shipped in before friday without paying a retarded price on shipping. Im leaving monday for a long Trip to South FL to pic up my new boat. GERRR! So this is why the 30k mile heater core is my option...its prob at least better then what I have in the jeep now. and I may do some work on the new 1 to prevent it from getting damaged or going bad

 

I wouldnt rush an install like this.... You can't survive without AC? My ac stopped working for years and last year I threw in one of those "sealers' cus I could care less what happend to the ac system at that point since It didn't work/hold a charge at all. This year it works OK but theres obviously to much oil in the system from the times I threw in those refrigerant cans, I have found a write up of not removing the dash to do this job.... it does require removing the glove box and cutting a hole in the dash behind it though, not like you can see behind there anyways. Aparently it takes an hour or so and whatever time a shop charges to refill the system, I might give it a shot some day.

http://www.cardomain.com/ride/653235/2000-jeep-cherokee/page-2

 

I would HIGHLY discourage the approach. The chances of making the situation worse by trashing the heater box is high.

Dismantling the dash, while tedious, is NOT a job requiring high skill levels or special tools. Just photograph all your steps (if your memory is not good), and you will be fine.

And yes, I have done this. Expect it to take your average DIY person about two days total (8 hrs/day). If you are experienced with dash work, it's probably more like one day, but rushing this job is an invitation to problems.

 

00 Jeep Cherokee Air Conditioner replaced

I have had problems with my air conditioner since before I bought it. I thought it was some thing simple but twas not so. About 6 months ago I had the thing checked out. They refilled the coolent and did a general check up. In June I had to have a new compressor and coolent lines and core and on and on. $798.35 it cost me. but she works great now. Better than any small vehicle I have owned or ridden in. So My wallet is empty but I am happy.

 

I have had problems with my air conditioner since before I bought it. I thought it was some thing simple but twas not so. About 6 months ago I had the thing checked out. They refilled the coolent and did a general check up. In June I had to have a new compressor and coolent lines and core and on and on. $798.35 it cost me. but she works great now. Better than any small vehicle I have owned or ridden in. So My wallet is empty but I am happy.

If you got your Compressor, Core, etc replaced for $798.35, you sir, just purchased the deal of the year.

I wouldn't have done the job for that price....

 

Well the dash didnt have to come out and I didnt have to cut anything just remove all the + Screws and then remove all the dash covers. I removed all the bolts along the base of thew windshield removed both kick panels then removed the center console and the bracket thats attached to the trans tunnel via 2 bolts. I removed the 2 bolts that hold the dash behind the kick panel and then went to the engine bay and removed the heater and ac lines and the 5 screws holding the HVAC box to the firewall. I then went back into the car and pulled the drivers side dash back about 3 or 4 inches. The dash on the passenger side has enough room to pull the dash back and pull the hvac box out without removing the wheel or anything on the drivers side other then the gauge cluster. Took me about 2 hours to get it out. Only used a phillips screwdriver and a 1/4 ratchet set with a swivel and a extension and a 13mm ratchet wrench for the 5 on the firewall. The heater core already was seeping water through lots of blue marks and the ac core was packed full of black crap and was eating away at the aluminum. I can post pics later. I should be done before night fall. at most would have taken me 6 hours AT MOST! But Im replacing everything including the box with all newer parts.

 

you dont need photos you can see all the bolts you need to take out just by sitting in the passenger seat. 1 by each kick panel, a few long the base of the windshield and start tugging on the dash you will find anything thats still connected and it will all move back far enough to pull the HVAC box back then out the passenger side under the dash. Getting it back in... I have yet to do Been taking my time.

 

You will also need this thread
http://www.jeepforum.com/forum/f11/heater-core-hvac-box-reassembly-886449/

 

I know this is old, but I'm going to attempt this in the near future. TwistedEvo8, how did it go getting it all back in place using your method? Also, where exactly do you disconnect the lines in the engine compartment? Do they disconnect and come out of the firewall along with the box?