Help w/AC on my 96 XJ

[Redsnake97]

I set up my manifold gauge kit on my 96 today to check the pressures, but it didn't seem that I could go much f/there.

Here's the pics of the Hi and Lo gauges w/the engine off. Outside temp was about 87 degrees

http://i14.photobucket.com/albums/a349/Redsnake/96XJACPressures001.jpg

http://i14.photobucket.com/albums/a349/Redsnake/96XJACPressures002.jpg

And here's the gauges w/the engine running. Temp about 110 degrees in front of the compressor and the temp in vehicle center vent was about 55 degrees.

http://i14.photobucket.com/albums/a349/Redsnake/96XJACPressures005.jpg

Does it look like I need to add some refrigerant??? thanks

[Redsnake97]

any other information that you might need to help me diagnose just let me know... :)

[90xj06]

whatsthe matter with the A/C it sounds like its working fine.

[Redsnake97]

Well it seems to take a long time to cool down the vehicle and I wanted to see if perhaps I should add some r134a to aid and make sure that there wasn't any leaks. I don't want to damage it if it's not broke, but making the AC work better would be really nice as well. thanks.

[xjtrailrider]

I'm no A/C know-it-all but I've been told by those who are that R134 looses some of its cooling ability after a few years and it is best to evacuate and recharge with fresh refrig. and oil. You cold also have air in the system causing some cooling issues.

[90xj06]

r-12 is much better than r-134a. the only reason they changed is because r-12 contained CFC's which depletes the ozone layer.

[lawsoncl]

Your high-side looks pretty high. (editted previous message as I was reading your guages wrong).

http://mysite.verizon.net/%7Echris83803/ac.jpg
http://mysite.verizon.net/%7Echris83803/ac2.jpg

[lawsoncl]

Also, the high pressure cutout switch is supposed to shutoff the compresser if the high-side reachs 450-490. I'm guessing you''ve check if the condensor is clogged up with debris, which leaves either overcharged (add any freon?) or you've got a plugged expansion valve.

If that first picture really is with the engine off for at least a few minutes, then I'm thinking you've got a restriction somewhere. Shouldn't the high side equal the low side if the eninge is off for awhile?

[90xj06]

look carefully at the gages they are very close to the same the numbers are different on the high than low.

[Redsnake]

All... thanks for the tips and insight. Perhaps I'm just paranoid and perhaps it's just the nature of the XJ... but it seems that my Jeep should be cooling off quicker than it does. Of course this last week the outside temps have dropped f/highs in the low hundreds to around 80 - 85 degrees... w/makes a HUGE difference in how my Jeep feels. :)

I just wish I could hook up my guages to my 16 yr old son's 87 Wagoneer to see what's going on there. His is still set up w/ R12 and the compressor won't even turn on. I may just take it to an expert for them to look it over. I think I'm in a bit over my head on this one... maybe. :)

(BTW, Redsnake97 and Redsnake are one and the same... had to make up a new userID to post f/home since I couldn't get logged on f/there. Thanks again to everyone)

[tommyr]

Couple other things to keep in mind....Engine speed should be at 1000rpm, system should be on recirc, doors and windows open, engine up at operating temperature. Something else to consider while you are cruising around is what color is your Jeep? A black one will naturally be hotter than a white one, making it that much harder for the A/C to keep up.

[lawsoncl]

look carefully at the gages they are very close to the same the numbers are different on the high than low.

Maybe I'm still reading the gauges wrong? To me, it looks like the short end of the needle points to the pressure scale, and the long side points to the temperature scales. Reading them this way, gives you the same pressure/temp ratios shown in the FSM.

-Chris