Got a little problem with the ac on a 1993 explorer 4.0. The a/c works but just barely and now its getting worse over the last two years. I am trying to recharge becasue it seems to be low. My problem is i dont know if its R-12 or R-134a. The compressor has a blue sticker that says it will work with R-134a or R-12 but i dont know whats in there. I also dont know if the system is orginal, bought it used. I know in 93 they had a few with R-134a. Any way to find out whats in there possibly?

 

R-12 air conditioning system is a low pressure system, when compared to R-134A. If you have a set of refrigerant gauges that could be used as an indicator, but since you say you are not getting much AC, I would not use as a valid indicator. The two refrigerants are incompatible. Though there were upgrade kits available to convert R-12 systems to R-134A (I do not recommend this, but thats my opinion). I would recommend having a licensed mechanic or dealer look at for you, because if R-12, you need a special license to by R-12 refrigerant as well as to reclaim and dispose of. If in doubt of type refrigerant , say it is really R-12, but you add R-134A, you could completly ruin AC system, let alone cause a major system failure (one of the AC lines to blow out or fry the compressor, because oil in refrigerants were not compatible either.) Hope this helps. Good luck.

 

r134a uses different sized ports. r12 gauges wont fit

 

Waste of time. IF the system is indeed low, there is a leak and you are doing no good here.

Otherwise, while both refrigerants CAN be mixed to some extent, anyway...define "works but just barely and now its getting worse over the last two years". Does the compressor run? Do you get all the different fan speeds? Have you checked the handful of relays and fuses involved in the system?

 

'93 original system was R-12. However, it may have been changed over to R-134a in the last 12 years. Look at the connections. If they are R-134a, the connections will be quick connectors, R-12 were threaded only (later models like the 93 would have a smaller diameter High Side than the Low Side). Like others mentioned, the R-134a connections are also a different size. If it was converted, whoever converted it should have put a sticker on it showing it was converted and the date. However, owner conversions may have skipped that step.

If it's low, as others have said, it's leaking. If it hasn't been changed to R-134a, it should be when you fix it this time.

 

I have 60 pounds R-12 given to me free on a job trade off, each 30 pound tank says when empty, "vent to atmosphere then break off the valve in the open position". Plus 35 of them small cans R-12 that I paid $.79 each.
In your case find out what you have in gas type and have someone you know pull a vacuum leak test before you refill.
I still see it where you want a AC part and the system is vented in 5 seconds in the field, part then pulled off.
.....=o&o>.....

 

Thanks for the tips. I think it is R-12 because of the connections, which are screw on black cap. My 90 F-150 which i had done, the connector looks much larger, so its leeding me to believe its R-12. I just dont see how the compressor could say R-134a or R-12 and be that old. I think ill take it into one of those $10 ac checks around town and see what they say. Id hate the thing to blow up in my face.

 

I see your in one of those cold states were you use AC only twice a year, just kidding. I have R134A in a 95 Rover so some where between 93 and 95 the Feds made manufactures do the change over to R134A. Check more than one place fror prices and stay away from the stealers.
.....=o&o>.....

 

Jerry is right the 93's were all R12, period. There were no deltas across the states at that time for this size truck. The compressor was likely changed in the past, rebuilt and a sticker placed on it that says it can be run either as R12 or 134a. This is not at all uncommon for rebuilts that are completely cleaned out and all seals replaced. No Ford in 1993 came with and either/or refrigerant sticker - the 2 gasses are not compatible.

One alternative is a gas called Freeze 12. This is a derivative that is compatible with R12 at about 1/10 the cost. But this is still regulated and needs a liscenced tech to install...but it could save about $200 in freon costs.