Cutty

Hey Team.....

99 XJ Classic

So my AC is not blowing cold at all..... I had a look (about an hour) for answers, but only got bits and pieces.

So the freon pressure read is fine (only using a hose from AC Pro), the compressor is engaging and I am pretty sure the blend door is working (well the motor is and when I move from hot or cold to AC the pressure/force changes).
One thing I did was feel the lines and the line that goes into the firewall is ice cold, but the only one that is cold (please see pic).
- Is that line being cold any indication for freon/working system?

The old girl had been refilled with R134 a while back, then sat for a year and when I tried it again the AC didn't work and pressure was a little low, so chucked some more Freon in to get the pressure back up, but still not having any luck.

Any help would be great before I head to the shop and pay $250 to vac and recharge.

CHEERS!

4.3L XJ

After you run it for awhile, is the return line to the compressor (the large one) cold? It should be cold enough to draw moisture out of the air (a good sweat in the trade)

Cutty

Thanks for getting back.

To be honest I’m not sure what one of the large ones is the return….?

I didn’t run the AC for long, just a few minutes whilst playing around with the blend door and testing if it got cold.
The one pictured was the only one to get cold after this time.

How long should I run the AC for?

Cheers!

agreen

That's not enough information, unfortunately. For 90% of your standard recharges, it is. But in this situation, it's not. Your system could be low on refrigerant with a bad compressor. So it could bring the low side down enough to give you that cold line and correct low side pressure, but the high side pressure should be in a specific band for the given ambient temp and humidity too. A set of manifold gauges are well worth the money ($50ish at Harbor Freight)

Absolutely not. Hook up to a set of manifold gauges and get the whole story first.

If I were you, I'd get a refrigerant charge kit from Amazon. Comes with a gauge set, a vacuum pump, a dye injector, and a sniffer. It's pretty much everything you need to do the job yourself, and it's like $150. You'll pay more than that for just the diagnostic at a shop.

So get the high and low side pressure readings, post them back here, and the real troubleshooting can commence.

Cutty

Thanks for your reply mate!

So I have a bit more info now - my mate used the truck during the year it was sitting and tested the freon as the AC wasn't working. He said it was super low on the gauge (almost empty) so he ran a freon charge using a kit from AutoZone and he said it cooled a bit, but not freezing.
So my guess (well after a heap of reading) is there is bugger all Freon in the system....? And this is what a cheap charge won't fix it this round, after being empty?

I also ran the AC on a drive for about 15min and even the smaller pipe isn't super cold now (it is 100 out here at the moment).

Additionally my mate put me onto a mechanic he uses and it will cost me $150 for him to vac, refill with freon and dye and test.... then go back a few days later to check for dye/leaks.
Is it best to just take it in and pay the $150?

Only thing I don't know is, if there are leaks does it need to be cleared out again, leaks fixed and refilled?

Cheers!

dzywicki

I got tired of being beholden to someone else for AC work. I got vacuum pump from amazon ($129) and bought a set of gauges off ebay for $50. There are plenty of options for ac manifold guages from Harbor Freight or amazon. My investment has paid for itself many times over. Have had two condensers get hit by a rock and lost AC. Pretty simple to replace those, vacuum down the system to test for leaks. Refill with R134 from Walmart ($4.00/can). Periodically test pressures on ll my vehicles with the gauges.
I even used this from Harbor freight a few times before I wanted something easier and got the other vacuum pump.

agreen

Or for $159, you can forever do it yourself.

Cans from Walmart are also now $9.

MaskedMallard

Are you able to fix the Jeep yourself, or do you rely on others?

If you can do it yourself, there are plenty of YouTube videos to help you through the process. Excellent advice has been given about buying some kits.

If you take it to the shop & if within afew days all the Freon has leaked out, you will need to pay for a refill of Freon, if you decide to repair the vehicle… If you take it to the shop & a leak is found, you will be given an estimate on fixing the Jeep. If you decide to fix the a/c and if technician is only able to recover half the Freon, because the other half is leaked out, you will have to pay for the repair, plus the amount of missing Freon.

Personally, I would go on the internet & buy the Freon with U/V dye already in it. First I would clean the engine bay really good, warm soapy water / degrease the engine bay. Pay attention to the a/c connections and make sure every component is clean, so U/V dye will show up. Buy about 6 cans & fill the system up to specification, with the equipment you have. After 3 or 4 cans have been used up, use the special U/V glasses to look for leaks. Figure out what parts you need & proceed from there. Keep in mind, the a/c system can run at a 100 plus psi, so if you make a repair, you literally just fixed the weakest link. The next question is, what’s the next weakest link. On my 2001, I replaced everything under the hood for my a/c system. If you need a a/c compressor pay the extra money for a new one. The shop I worked had seemed to have a 50/50 success rate with rebuilt a/c compressors….

Cutty

Thanks for you reply mate!

I have fixed everything so far I needed to (with a heap of help here, thanks!), but I am wondering if the AC is something I can/want to mess with.... or just pay $150 and get it done professionally.
I spoke with the guy who I would take it to and he is going to use the sniffer first and plus will test the system before vac and fill.

I hear what you are saying re having to pay for another fill if there is a leak etc and that is my only concern really.

Additionally there is Freon in the system and I don't want to put that out in the air myself....

Cheers!

4.3L XJ

Run it for about 15 minutes. One line will be hot and the other cold at the compressor

Cutty

Thanks mate!

Yeah the small line is cold and the bigs all hot…. But still warm in the car.

Cheers

4.3L XJ

Mate, something is not right here. the small line that goes to the condenser core in front of the radiator is the one that is supposed to be hot. Verify where your lines go

Cutty

Thanks mate

I touched every line that is associated with the AC (bearing in mind I am not a mechanic) and the only one that was cold is the small line that comes out the firewall (pictured in my first post).

I can run it again tomorrow and try them all again.

4.3L XJ

Well mate, it sounds like your refrigerant is running backwards. The only thing I can think of is that you have a valve problem in the compressor. If you have a set of AC gauges so you can check the pressure on both lines while running you could confirm that

Cutty

I’ll run it for 15mins today, check the lines and let you know.
If that’s still an issue I guess I’ll get some gauges and test or just take it in and get my guy to check it/vac etc.

It’s 100 here for the next 10 days and no AC is a battle!