A/C Not holding charge

My brothers 2000 xj has a problem with its a/c it will not hold a charge. We just charged it yesterday and today nothing but hot air. We had it done a Jiffy Lube. We have used them in the past on my mom's xj and my xj and the recharge went smoothly. They re-recharged the a/c this morning at no charge and this evenig my brother reports that it has again stopped functioning. I am assumeing that their is a leak somewhere in the system. Being the jeep expert in the family, it has fallen to me to fix the problem. How do I track down the leak in his jeep?

Any ideas would be helpful

thanks Adam

I have seen these UV lights with special glasses for seeing freon leaks in AC systems, at the Auto Parts store, like Auto Zone. You'd have to buy a can of appropriate freon, juice up the system, wait for it to leak, and watch it with the special UV light and glasses, or take it to someone who specializes in AC systems. We used to have a guy who did auto AC systems in our town. When he retired, hugh loss to the community.

Funny this should come up. I also have a 2000, and am having one hell of a hard time trying to isolate the leak. I have replaced the condenser and all o-rings in the engine compartment. I have had a dye leak test done twice, and still no sign of leaks. I have taken apart the dash and with a UV light looked at the evaporator for any signs of dye. It worked fine for a week after the last two charges, but still no avail.

Worst part is my junk is black on black on black and it just soaks up the heat. Just subscribing to this thread to hopefully get a grip on this gremlin. Post up if you fix it.

My roommate has a 2000 that has the same mystery leak. I told him not to, but he had pepboys look for the leak and they said they coudn't find it, but that it might be buried within the dash. We haven't had time to tear it apart yet but I would look there. I'll let you know if we find anything when we get to it.

From what I've gathered, XJs are known for evaporator leaks. Perhaps the refrigerant and dye is leaking within the heater box, as Reaper alluded to. Of course, tearing out the heater box isn't the most entertaining way to spend an afternoon .

If you know you're going to be recharging the system, why not replace the O-rings while you're at it? You'll need a special "spring lock" removal tool to disconnect the evaporator and condenser lines, but you may be able to rent it from the auto parts store. The O-rings cost only a few dollars and make for cheap insurance.

Often an AC leak will carry the AC oil with it and leave an oily spot. So look for an oily spot around the joints in the system.

The seal on the front shaft for the compressor can leak and when it does, its often bad. Its hidden under the clutch, so its tough to see.

Again the UV dye is the way to go for leaks that aren't obvious and even then they don't always work. You'll need the special light to help find anything NOT obvious.

Pro's will have expensive refrigerant sniffers that they wave around the lines and connections and see if they can detect the leaking refrigerant.

Check if there is a recall or extended warranty on the evaporator. Many Chrysler products in the 90's had a horrible problem with evaporators forming pin-hole leaks. The supplier making the evaporators didn't use the proper procedure for cleaning out the acids used in production, the acid would lay in the bottom of the evaporator and eat a hole in the evaporator. "If" your XJ was one of the vehicle affected by this, there might be an extended warranty to repair the evaporator.

Ben H said:

Funny this should come up. I also have a 2000, and am having one hell of a hard time trying to isolate the leak. I have replaced the condenser and all o-rings in the engine compartment. I have had a dye leak test done twice, and still no sign of leaks. I have taken apart the dash and with a UV light looked at the evaporator for any signs of dye. It worked fine for a week after the last two charges, but still no avail.

Worst part is my junk is black on black on black and it just soaks up the heat. Just subscribing to this thread to hopefully get a grip on this gremlin. Post up if you fix it.

Click to expand...

I finally found my ac leak yesterday... i was looking around for days with the uv dye and i finally spotted a tiny bit of glowing residue around the clamp band that holds the accumulator/reciever dryer on.

Anyway I found a CRAZY deal on a new part here:

http://www.autoairplus.com/ProductDetails.asp?ProductCode=04-4294N

the part for the 2.5l and the 4.0l is the same. However, this will only work with 97' and up xjs. It arrived in two days and i've got it, build quality looks fine, its the right part.

Ill put it in later today. I am really looking forward to having AC again...
:guitar:

If you have a leak big enough to loose the full charge in 12 hours, you might be able to isolate it by sound. Pressurize the system while the truck is cold, open the hood in a quiet place, and listen for the hiss.

To find a leak in an uncharged system, first look for an oil stain on the system parts. If that fails, make an adapter from one of the cheap fill hoses and some barbed fittings, connect the hose and charge the system with compressed air to about 35 psi. If you want to be professional, get a bottle of dry nitrogen. DO NOT RUN THE AC WITH AIR OR NITROGEN IN THE SYSTEM! Fill a squirt bottle with water and dish soap. Go to town under the hood: Every line, connection, the whole condenser coil. Look for bubbles. If you find no little bubbling spots, the bad news is the leak is probably under the dash. Break out your big rubber hammer and hit yourself in the forehead(easier then waiting and hitting your head on the dash!) then repeat the soap treatment inside.

After you found and repaired the leak, have an AC tec vacuum the system down and leave it for 24 hours. If it still holds a vacuum, have it charged.

That is dirt cheap! Good find. I've replaced the accumulator both times I've opened the system, good to know that it wont cost me $60 again. Thanks for the link.

darjevon said:

I finally found my ac leak yesterday... i was looking around for days with the uv dye and i finally spotted a tiny bit of glowing residue around the clamp band that holds the accumulator/reciever dryer on.

Anyway I found a CRAZY deal on a new part here:

http://www.autoairplus.com/ProductDetails.asp?ProductCode=04-4294N

the part for the 2.5l and the 4.0l is the same. However, this will only work with 97' and up xjs. It arrived in two days and i've got it, build quality looks fine, its the right part.

Ill put it in later today. I am really looking forward to having AC again...
:guitar:

Click to expand...

Thanks everyone, I will take a look at my brother's jeep this mothers day.