I have an 01 w/2.3L DOHC 4cyl. Over the last few years the A/C died a slow death in terms of producing cold air. I didn't bother doing anything about it as I don't use it much anyway. But now, with temps > 100F and high humidity, I'm wondering what the likely cause is. A/C doesn't make any noise. Is this just a need for recharging? How long is a charge supposed to last?
Thats a good sign that it is just low/out of freon
The Air Conditioning has a low pressure switch that disables the compressor from running if there is not enough freon.
depends on why it leaked in the first place. If it SLOWLY lost its cooling capacity, the chances are yiu have a SLOW leak and might get a whole summer out of a recharge. I like to find and fix all leaks, but a system that looses 1 to 3lbs. of freon over 4 or 5 years' time will not be easily found. There are some reputable auto maintanance/repair chains that do air conditioning correctly. Do your homework. Ask if they can pull a vacuum on the system of 30 lb. and if they will hold it for 10 min. to check for a large leak. No change in neg. pressur, and your good to charge.
Just for your edification that's 30 inches of mercury. vacuum is measured in in/hg and in/H2O for you variable venturi carb fans. In 1991 I think the use of the black rubber line connector orings were in use. They should be changed to the teflon green oring, they don't stick to the metal and tear and the oring grooves on the line and the female receiver side of the line also should be cleaned of the rubber sticking to the metal. Scotch pads work pretty good. clean in a round and round motion not back and forth. Also the compressor shaft seal will need replacing after 15 years. With the system charge you'll be able for futher diag as to pressures and compressor noise. This is an R12 system correct? Take it to the Ford dealer and have them properly convert it to R134a. The price per oz of R12 to R134a is considerable. And never use any other refrigerant than spec define. Hey what kind of air conditioning did the settlers use. Evaporating sweat. We so energy unconscience, it's pitiful.
Thanks for the reply. That's the best answer I hoped for, the worst being that the A/C on this model was notorious for big$$$ failure as soon as the warranty expired.
Seeing as the air is still just a tad cooler than ambient when on full blast, I'm inclined to try a DIY charge.
I think it was SLOWLY losing cooling capacity from day one. I rarely used it (only about 11K mi on the truck), but probably had reason to suspect a problem while still under warranty. Oh, well...
In the REALLY hot weather yesterday, on full blast, it seemed to be producing slightly cooler air than ambient, which is odd because I'd previously thought it completely dead.
I don't think there's any chance this is a large leak. I'll check around, but I suspect a DIY fix is the most $ I'm willing to spend on this right now.
May I point out that the r-134a systems are sensitive to total system pressure. My two vehicles, in hot weather, turned out to have similar symptoms. You should first check system pressure w/o engine running, then when system is operational. Do the low pressure side only! The cause in both the '98 Ranger and '99 Explorer was because of too much refrigerant.
Check out this site;
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and this one for what you should expect to see for system pressures at various ambient temps.
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Be aware that the compressor will cycle rapidly if the system pressure is too high or too low. When things are OK, the compressor will cycle slowly to maintain correct operational parameters. At idle, and around
90 degrees, neither of my vehicles' compressors cycled, only at roadspeed did they disengage/engage.
Center air discharge temperature should be between 35-50 degrees, depending on ambient temp, mine both cool the air to about 40 degrees with outside air @ 70-75.
Ford also puts a flourescent leak detector dye in at the factory, so you shouldn't need to put any in yourself. Just find someone with a UV lamp and you're good to go to check for leaks.
All automotive ac systems leak. Any system using seals, especially around rotating shafts like on the compressor, is going to leak. Having to have a system topped off every couple of years is normal. There is always going to be some flex in threaded fittings sealed with o-rings, another leak, and spring locks were invented to allow ac technicians to stay in business.
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