Will an AC system maintain pressure of say 45 lo and 225 high when charged and even when refrigerant has leaked out?

 

It depends on the leak. If the leak is small then it will hold the pressure (charge) for a while and then the charge will leak out and pressure drops.
Some big leak will leak out the charge in less than 15 minutes. Some leak will take about a week.
Most leaks comes out of the Low Pressure valve (where you connect and charge the AC system). Make sure you tighten the Low Pressure valve good otherwise the AC will leak out from there. Sometimes you just have to replace the Low Pressure valve to fix it.
To find for leak, you can buy this UV Leak Detector. It is composed of a colored orange google, a UV dye colored liquid that you inject to the Low Pressure valve with a syringe. Put some charge (3 cans if completely empty of charge). Make sure that the AC is set to MAX and fan to HIGH. You use your goggle and the leak will shows as color green.

 

I've been out there all afternoon with it running, no leak that i can find. I checked the condensor, lines, evap core, all fiitings. No dye shows up at all.
What symptoms would I have if the orfice tube is clogged or leaking by?

 

Is this your house system?

 

Pressures seem within limits (depending upon outside temp), but what is the problem..Is it not cooling properly?

 

No, not the house. My Suburban.
Vent temps only getting to 70 when ambient is 85-90 an only blows cool for a few days. It's a retrofit as well. I figured a leak but couldn't find it. Since it got dark, I found the leak by using dye. It turned out to be a rubber hose to crimp fitting running to the rear unit. Can I cut the hoseand use a clamp or does it need to be replaced?

 

Suburban... Cough choke puke...

 

Yeah, I know. But for 700 bucks what do you expect?

 

the hose needs to be replaced it is cheap like 20.00

 

I think we found the problem! Yes, it needs to be replaced....with a Ford product! And no! You're quote was not "doctored" in any way!

-Matt

 

keep in mind to check the seal behind the clutch for the compuressor. Most A/c systems leak there and no one thinks to check there. Becareful if you pull the clutch/hub off, cause there is usally a washer behind it to provide the proper air gap.


Pull hub off, and you'll see some foam pad inside the compressor, if it's soaked then you found another leak.

If it is leaking then you can either find someone who will replace that seal, or replace the compressor. I wouldn't recommend replacing the compressor with a remain. They never last more than a couple of weeks. I've gone through 4 of them before I found one that worked....OEM from dealer..lol


Oh to answer your other question about "<TABLE class=tborder cellSpacing=1 cellPadding=4 width="100%" align=center border=0><TBODY><TR title="Post 1652562" vAlign=top><TD class=alt2>What symptoms would I have if the orfice tube is clogged or leaking by?</TD></TR><TR><TD class=thead colSpan=2>05-29-2004 01:27 PM</TD></TR></TBODY></TABLE>
I've never seen one that leaked by, but if it's clogged then the low side pressures will go up, and I supose if it is leaking by, then the pressure would be low.

Last thing...when you convert to R-134 you only use about 85%-90% of the advertised R-12 charge amount.

 

Let's not forget about the hot water system. Your A/C could be working fine except it's also trying to cool a hot heater core. Make sure whatever controls temp is working properly. An easy way to test this is to pinch off the water lines going into the heater core.

 

Campigrig, thanks for the info. I did replace the compressor with a reman unit (1 year warranty) But the dye is not showwing anywhere around the compressor. I plan to replace the hose but the entire line is about 2 feet of rubber and 8 ft of hard line (150 bucks from LMC). I just need to get out there and pull it.
Rob, I would have never thought of that. Thanks for the tip.

I'll post back after awhile and let you know what I find.