• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

AC has suddenly developed massive leak, planning full rebuild

anthrax323

NAXJA Forum User
Location
San Antonio, TX
So my AC system has gone from holding a charge for ~10 days at a time to holding a charge for less than 24 hours (at which point there is virtually no pressure in the system at all - compressor won't even cycle). I replaced the high- and low-pressure diagnostic port Schrader valves, as these were leaking last time something like this happened, but to no avail.

Given that I'm moving back to TX soon, and I *NEVER* want to deal with this again, I'm going to do a complete system rebuild. New compressor, evaporator (which I know is bad), and so on.

Below is the parts list I've compiled thus far:

  • Compressor
  • Condenser
  • Evaporator
  • Heater core
  • Hose assemblies (hard and soft lines, low and high pressure)
  • A good set of AC line tools
Now I know I should also get the foam gaskets for the heater box/core (whatever the whole assembly is called inside the passenger compartment), but am unsure of where to find them. Is this a dealership-only part set?

Also, should I shell out extra cash for a brand-new compressor, or take my chances with an AutoZone remanufactured unit?

In any case, please let me know if I've missed anything... I really want to make sure this repair is good for at least 10 years, so if you know of any reputable part manufacturers or suppliers (other than AutoZone) where I can get good deals on these components, I'm all ears.

Thanks in advance!
 
Personally I would put some leak tracing dye in the system to see where the problem is. As far as the compressor, if it ain't broke don't fix it is my motto.
 
What year is it ? done both ac systems on a 99 and 96 I got the parts in a varity of places Rock auto, dealer ship, jeep air, and Ebay. I shopped a round for the best price on both. all the part cost me about $550 Spent anther $200 on a set of disconnect tools, guages, and Vacume pump.

12 hr of labor total.

I also did the heater core while i had the dash out.

I would say the only thing i would have done different would have been new sensor. I did not replece them at first and one failed on the 99 shortly after i completed the job.

I have made my money back twice over doing ac work for others.
 
Thanks for the input guys. I've bought a UV pen light and a can of R134a with UV dye (but no leak stop), but am considering taking it a step further and buying a sniffer from Harbor Freight (it's not a great one, but what little testimony I've found on the product has been positive).

I agree it's not the most sensible thing to do (replacing the whole system), but I aim to have this vehicle until it is hauled off to the scrapyard and would like to avoid dealing with another AC issue for as long as I possibly can.

I'm going to start with the dye and sniffer, and see where it goes from there. Thanks again for the input.
 
Thanks for the input guys. I've bought a UV pen light and a can of R134a with UV dye (but no leak stop), but am considering taking it a step further and buying a sniffer from Harbor Freight (it's not a great one, but what little testimony I've found on the product has been positive).

Good plan.

I agree it's not the most sensible thing to do (replacing the whole system), but I aim to have this vehicle until it is hauled off to the scrapyard and would like to avoid dealing with another AC issue for as long as I possibly can.

I'm going to start with the dye and sniffer, and see where it goes from there. Thanks again for the input.
 
Most auto parts stores carry them (typically called an AC manifold gauge set, I believe).

I've done the dye test and found 2 or 3 leaks:

1) Lots of dye appeared in the high pressure diag port. Unfortunately, I'm not sure if this is fresh or due to past diagnostics (plus, it was replaced immediately prior to this round of charging with dye).

2) It looks like some dye is present at a flanged coupling near the firewall (hard line coming from the condenser). Not 100% sure on that though - very little, and the pattern doesn't make sense for a leak at a union like that.

3) Looking in through the "floor" vents up front (where the center console meets the underside of the dash), there appears to be some dye visible in the air source above (the square hole in the bottom of the AC/heater core). I guess this is further confirmation of an evaporator core leak, which might be a substantial one now given the visibility of dye... Assuming it's not some other UV reactive substance that's misleading me.

Argh. Guess the evap core is unavoidable now. I'll probably replace the accumulator and the hard lines (with service ports) just to be safe, since they're not all that expensive anyway.



Where can you buy the lines that attach to the top of the AC pump on a 97?
The dealership, just about any auto parts store, online (see here).
 
Last edited:
Looks like through JeepAir.com, I can rebuild the whole system (minus the condenser) for $582, shipped. This includes new hard and soft lines, a new accumulator, a new evaporator core, a new heater core, a new compressor, and an O-ring kit.

Honestly, I'm tempted to source a condenser somewhere else and do the whole shebang for less than $700.

At the same time, I'm seeing that these are all aftermarket components... Think I might take a chance with quality going through JeepAir.com? The compressor is the biggest concern taking that route.
 
Hello anthrax323,

I am in the same boat as you.
Mine is a 87(converted 134a), (80,000 original miles)and the compressor went south a couple of days ago. I went to Jeep Air and planned to get everything I needed for a complete redo. I asked about the warranty on the compressor, answer was NONE if dye is introduced to the system. I bought everything from ACKITS.com http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=Jeep
Good Luck with yours
 
Thanks for all the input, everyone.

I ended up getting a stellar deal from RockAuto - got a complete new system (compressor, evaporator, condenser, accumulator, O-ring/gasket set, heater core, suction/discharge lines, and liquid line/orifice tube) for $502.75, shipped. Thus far, the compressor, evaporator, and accumulator have arrived... I might get to start on this on Monday with any luck.

Oh yeah, and I picked up a 3 CFM vacuum pump (part number 66466) from HF for $119.99 thanks to a 20% off coupon that expires on August 2nd. This pump is apparently pretty damned impressive even at normal prices, so I'm quite happy that I wrangled a solid discount.

When it came to a manifold gauge set, I ended up going with the MasterCool 89660. Haven't found much on it, but all signs seem to point to it being a quality unit (easily rebuildable as well).

I'll do my best to fully document this, but given that it's consistently 100+ F and humid as hell right now, I might run short on patience and just try to get it over with.
 
I just realized I have yet another question... XJOutsider, you mentioned changing the switch - looking at my current system, I see two switches. One is on the accumulator itself, and the other appears to be on the compressor output line. They both seem to be working fine, and appear to be easily accessible - should I go ahead and replace them now, or just wait for a failure? I assume the system would need to be discharged in order to replace them... Am I correct?
 
Well, the process has begun. I believe I have found the leak (not sure how the hell I missed this before unless the evap just recently puked all the die out):

ac_leak.jpg


That's... Not good. The tear-down began last night, and thus far I've removed the front seats and the majority of the dash fascia. I have run into one snag, however...

What's the best method for disconnecting the HVAC mode knob (the middle one that is pneumatic)? It looks like I could pry a couple nuts off (as they're not threaded) and remove the soft rubber piece holding the hoses in place, but I'm wondering if this is even necessary since I've disconnected the vacuum line junction behind the glove box/under the passenger airbag. I'm getting the feeling I can just leave the knob connected... Am I correct?

(Just musing about what to do this afternoon, as I just got to work.)
 
The dash comes out in almost one entire piece. Once you get it out, it should look something like this:

15543_654494500977_36618587_37852160_7951639_n.jpg


If you're following the FSM, it states to remove the steering column. This is NOT necessary by any means. All you have to do is remove the steering wheel (using a puller of course), and then tilt the column all the way down. You'll then be able to slide the dash up and over the top of the column.

The inside of the Jeep with the dash out, and the HVAC box still in, will look like this:

24982_686725789217_36618587_38814256_3133554_n.jpg
 
Beautiful, thanks for the tip and pics - glad to see the dash wiring harness can remain in place (along with the pneumatic AC control switch).

Quick question though - is it absolutely necessary to remove the steering wheel? I'm guessing it'd be a horrific pain in the ass otherwise (navigating the dash over the wheel), but I'm looking to take all the [reasonable] shortcuts I can.

It actually looks like I can put a few pieces back on before removing it (to reduce clutter and minimize the risk of losings screws), which is awesome...

Also, what are the locations of all the bolts I'll need to remove to pull the dash out in one big piece like that? I've located 4 along the leading edge of the dash (near the windshield - 2 nuts, and 2 bolts), along with the two in the center above the center console, as well as one on each side of the vehicle near the kick panels (bottom of each A-pillar). Are there any others I need to be aware of?
 
If you don't remove the wheel, you'll have to remove the entire column. Unless you want to break the dash down into smaller pieces and remove it like that. I wouldn't recommend that. Rent a steering wheel puller (or invest in one, they're good to have!) and yank the wheel off. Even doing that, it's a tight fit to pull the dash over the column, but still do-able.

As for all the bolts, you've got them all covered. 4 on top, 2 on bottom.

I've done two of these so far (hence the pictures haha). Not a hard job by any means, just very time consuming. It helps if you can round up a couple friends who are somewhat vehicle savvy. First one we did, we had two people pulling the dash and one person doing the under the hood work (draining coolant, discharging AC, unhooking lines and unbolting HVAC box from the firewall). Same thing on the installation, two in the Jeep and one under the hood. Start to finish we had it done in 3 hours (including refilling coolant and recharging AC, along with testing and checking for leaks before hitting the road. The second one, it was just me and one other person, and that took about 6 hours or so start to finish.
 
Thanks a ton for the input buddy - funny thing is I actually winged it right as I got home, and about 3 hours of work later I've got the handler (core, whatever) sitting on my dining room table. I didn't disconnect the primary harnesses in the driver's side kick panel, nor did I remove the steering column stalks (signals/wipers), but did manage to swing it out enough to get the whole unit out without too much of a struggle... Removing the steering wheel definitely made things far more accessible.

This puts me at about 5 hours of work total thus far, and I'm ready to replace the heater and evaporator cores. Seems pretty straight forward, but I haven't managed to find any adhesive foam at any local auto part stores. I'll be swinging by Lowe's tomorrow to see what kinds of weatherstripping options they have that might suffice (just for the evaporator core - the heater core already has its foam surround). If you have any tips regarding what type of foam to buy, that'd be awesome (i.e. open or closed cell, approximate thickness and width)!

Things are going far more smoothly than I expected though, thanks to your advice. I honestly think I might be able to knock out the rest of the system removal and installation of new parts tomorrow evening, and leave re-assembly of the interior for Friday (might even work from home so I can take my time). This depends entirely upon how quickly I can replace the condenser, though, so it might not happen.

A couple coworkers showed interest in lending a hand when I sent out a company-wide e-mail looking for a vacuum pump to borrow, but alas have not followed through yet. I can't imagine how much easier this would be with a competent set of extra hands, lol. The only real pains in the ass thus far have been that damned 5th nut on the firewall (mine was extra special, as a wiring harness was secured to the post using a thin lock washer/nut thing), and trying to use the piece-of-crap disconnect tools I bought from Sears (white plastic nightmares).

Oh well. Progress is progress. I can't wait to see what I find when I tear into the air handler... (What the hell is the proper name for it, anyway?)
 
Not a problem at all. Sorry I didn't get back sooner yesterday morning, work got in the way of my NAXJAing lol.

As for the foam, we didn't put anything back on the new evaporator. Just opened the HVAC box up, and swapped the evap and heater core, then threw everything back together.

The one thing I didn't like is the way they did the insulation on the HVAC box, it's like they never meant for it to be opened up in the first place. The only way you can get in is to cut the insulation around it.

I'm guessing by handler you're referring to the box that houses the evap and heater core. I call it the HVAC box, and I think that's more or less what the FSM calls it as well.
 
Back
Top