ZeppmanR

My 93' Cherokee XJ has/had (the air-conditioning no longer works) a system that used the R-12 refrigerant. I know that you cant buy R-12 anymore, and are now supposed to use R-134a. My question was do I have to replace the AC compressor with a newer, R-134a, model or can I just get the R-12 compressor recharged with R-134a. The reason I ask is that I was told that using R-134a on its current system could cause problems. Any info on this and actually how to recharge the refrigerant would be helpful. thanks

offroadnut36

No, you have to swap out fittings, hoses, compressor, etc... It's called retrofitting, and it can get pretty complicating. Recharging is as simple as going into autozone and getting a recharge canister(btw never get the ones that say or have anything to do with stop leak, they suck and will hurt your a/c system) Or Go to a shop and have them recharge it for you the better/right way.

Caish

About $60 at Harbor Freight, get a set of gauges.
Buy the adapters, about $12 or less.
Remove the lines and get some A/C flush. $12 to $15. (R12 oil is not compatible with R134)

I would also suggest getting a new a/c dryer typically around $25 for most applications.
Remover the lines from compressor and the A/C dryer.
Now use compressed air and blow the lines out. then poor the flush into the lines and blow it out.
Now turn the compressor by hand and pump all the oil out of it.
Put the lines back on.
Hook up the gauges and adaptors. I found that sometimes the adapters screw down to far and push the shrader valve to far and cause it to leak after removal. Typically I'll only screw the adapters down 3 to 5 turns to cure this issue.
Now add a can of R134 oil.
then start adding R134 gas, your gauges are marked with a pressure and tempatures. Your wanting to use the temps on the low side.
You want the low side to be around the 40 degree mark. The high side should be no higher 275 to 300psi. It will run lower if you put a fan in front of the condenser. Do not over fill it. Most cars/trucks have a weight in pounds and ounces that the system will hold.

Happy trailing.

offroadnut36

You have to vacuum all the r12 that's in the system out and dispose of it properly. It's highly illegal to just let it out into the air.

djb383

I believe anytime a/c lines are disconnected, a vacuum should be pulled on the system once everything has been reconnected. Doing this removes moisture, air and allows for leak check of the system before recharging with refrigerant.

http://www.autoacsystems.com/_faqs/d...ompressor.html

giwill

yeah you need to do pull a vaccum on the system you can rent the vac pump from autozone it will cost you a 300 dollar deposit but you get it back when you return it. This is not hard to do and you can also get the amount of freon that your system holds from them most systems hold like 23-24 Oz. or two cans

Bustedback

Just have a shop fix the leak and recharge it with R12. It is still available, just not to the general public.

Caish

I forgot the vacuum. Air powered ones can be had for under $100.
I got a vacuum pump too.
As to collecting R12, you ever heard of a Hoax? R12 is heavier than air. It does not get to the Ozone, you want to real truth. The patent was running out on R12 so Dow Corning didn't put up a fight over it. Just make a new stuff, new Patent more money.

Technically your suppose to reclaim it. But you already said it was empty RIGHT! so no need for the expensive reclamation.

I have seen guys sacrifice a can of R134, change the system with one can then bleed it back off and charge it. Seemed to work for them, not my way. Only time I don't pull a vacuum is if I'm out on the road and need to fix the a/c NOW. Then I'll redo when I get home with a vacuum.
Vacuuming the system does two things.

1. IT removes the humidity and moisture from the system, makes the dryer last longer.
2. You can check for leaks in the system using the gauges. Pull a vacuum and close the gauges and let it set for an hour or two and recheck the vacuum. If its still where you left it, your good to charge.

If you have a leak, you can get a bottle of die, its yellow, and you add it to the system and then use a black light to look for the die. It will glow.

EVcherokee

Yes it does, this is common knowledge. R12 also doesn't destroy itself when it reacts with ozone gas either. R12 is a catalyst and will continue breaking ozone into oxygen for roughly 130 years Your conspiracy theory works in a motionless world, but in that world ALL the gases would seperate. Oxygen would leave the surface of the earth the be replace with %100 nitrogen. All plant life would die too because of lack of CO2, which would also be miles obove the surface of the earth. In our world wind currents caused by solar heating keep things mixed among other things. Water vapor is heavier than air too and there are still clouds in the sky. Pick up a chemistry and physics book, its all in there..

Most of the refergerants we use today were invented in the 30's and 40's and many patents ran out in the 50's. Along with DuPont, Atofina Chemicals (formerly Elf Atochem), Ineos Fluor (formerly ICI Klea) and Honeywell (formerly Allied Chemical and Allied-Signal) were all major vendors of R-12, and are today major suppliers of R-134a. The "other three" did not pay royalties to DuPont for their sales of R-12, and do not for R-134a.

Man, don't be a douche, do the right thing its only like 25-35 bucks to have it pumped and you willn't make the rest of use look bad.

EVcherokee

134a is an obsolete refrigerant. Yes it can hurt your system bad and most of the "R12 friendly" recharge cans just contain R134a with another R12 compatible gas to carry the oil. Sometimes they work sometime not. If you can buy it with out a section 609, it can hurt your system.

Starting in 2011 R134a will be banned in new cars in both europe and the US. Both the EPA and the EU also have plans to completely ban R134a like R12. The difference in boil/dew points between r12 and 134a is about 40 degrees. The difference between R414 and R12 is one degree and R414 is widely used, approved for motor vehicles, and available with a "section 609 permit".

Check out my thread, I'm in the same boat
https://www.cherokeeforum.com/f2/any...ot-shot-51851/

Modrod

Yeah, a lot of people don't realize what a scam the R12 thing was. R134 is more toxic than R12 and is really hard to keep in a system even if it is made for it. I think it's funny that R12 is heavier than air and was blamed for destroying the ozone. I think it was caused by industrial and commercial emissions rather than R12. Eliminate everyone making your ex patented Auto AC gas, then patent your new crappy one to capitalize on. lol
DuPont has been a shady corp for almost a century.