Convert your automotive air conditioner from R-12 to R-134 Refrigerant.

If you have an older car it may have R12 refrigerant in the air conditioner system. You can still buy R12, but it is very expensive. If you are ready to convert your system to R134, here is a brief explanation of the procedure with a few insider tips to help you. To begin you will need a conversion kit with all the necessary materials. It will include: 2 new adapter fittings, 2 -3 cans of R-134, and a hose with adapter. Once you have all the materials, you can begin the process.

The first thing you have to do is have the R12 recovered with a refrigerant recovery machine. (It is illegal to just open the valve and let it out in the air.) Now that the air conditioning system has no pressure, it is time to install the new valve kit. At this point some people freeze up (no pun intended) because they are afraid of mixing up the adapters on the high and low pressure ends. Don’t worry, they are different sizes. The bigger one goes on the low pressure side of the system and the refrigerant hose will only connect to the low side valve. It is pretty hard to mess this up.

Now that the adapter valves are connected, it is time to start the car and put the air conditioner on high. Turn the blower fan to its highest setting as well and open the windows. Grab a can of R134 and hook up the hose and T valve that came with your kit. With the hose hooked up to the can begin to twist the T valve until it punctures the can. Then open the valve to let some freon out and purge the air in the line. Turn the can upside down and hook it up to the low side adapter valve. Now slowly open the valve and let the Freon flow into the system.

At this point the compressor will begin to cycle on and off. Don’t panic, this is normal. Keep adding Freon until the system begins to cool. You can feel the low pressure line begin to get cool and condensation will accumulate on it. (Do not grab the high pressure line. It can burn you.) You probably will not need all 3 cans and be careful not to overfill the system. If the air conditioner is still not cooling after the second can, something is wrong. You may have a leak in the system or some other difficulty. Do not be tempted to keep pumping Freon in the lines. If the low side line is cold and dripping with moisture you are done. If you have a air conditioning manifold gauge set, the low side should have a pressure of 40 – 50 psi. Good luck and stay cool!

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Comments on this article:

» left by John (3 years 104 days ago.)

BTW, I have a CA state moble ac lic and years of experiance, Use a Ester type oil and it works with R12 & 134A. The ONLY !!!! reason you evacuate the system is to remove moisture PERIOD ,, I am so sick of this "You have to remove air it takes up space" this is just plain wrong and ignorant.
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» left by Bill from Georgia (1 year 138 days ago.)
Hello...I have a 1990 jeep cherokee and I am thinking of converting A/C system from R-12 to the 134. How and do I go about this? What would the cost be if I took it to a shop to have this done.

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» left by Anonymous (3 years 101 days ago.)
removing the air also keeps the head pressure reasonable , and as air is not condensible it does take up space meant for liquid refrigerant y'all hacks with your mail order licenses and not thought for the physics involved in removing heat from a space make me sick and cost your customers time and moey, yes a retrofit can work well if you take the time to add an oil additive and evacuate the system, it is not a complete job but it is servicable.
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» left by Anonymous (1 year 111 days ago.)
Do you mean that air is not compressible?  That it certainly is.  I've nere heard of air being non-condensible.  Webster's defines the verb condense as to make compact.  So, what is up with an air compressor if it can't be compressed?

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» left by Anonymous (115 days 18 hours ago.)

What's meant is that air does not act as a refrigerant inside the air conditioner.  A proper job demands that you remove the air that enters the system when you open it to the atmosphere...and keep in mind that you will need to replace any lubricant lost while removing the old refrigerant. 

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» left by tom from california (62 days 5 hours ago.)

+1 The air does not condense, meaning turn into a liquid, at these pressures, would need to be much higher for that to happen.  So the air stays as a gas. The original comment is still correct - It did not say the air would not compress, which it does. But it still takes up space.

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» left by (1 year 141 days ago.)
When converting to refrigerant 134 from R12 in your automobile, do you have to change the oil in your compressor?

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» left by jb from broomall pa (1 year 121 days ago.)

yes it was amusing and informative to. you take the good and leave the funny,thats all.

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» left by Memoryz from AZ (1 year 119 days ago.)
WOW! and you guys can vote!

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» left by Matt from NJ (1 year 113 days ago.)

This one of the last items I need to fix before selling & want to get the AC working again as cheaply as possible. Any help with these questions plus any additional advice is greatly appreciated.

Okay folks, so here’s a little background.... I have a 1997 Honda Accord w/170K miles, which I am just about to put on the market. I have poured a lot of $$ into this car & just had the entire car painted by Earl Schrieb (real $%&*$%& job on prep & sanding) I would grade the paint quality a C+.

So here it is…I just purchased a new (rebuilt) AC Compressor to replace the current one which ceased. What I was thinking of doing was to have the new compressor installed by a local garage then use one of the DIY Freon "R" kits (R12 or R134??) to refill the system (which is already evacuated) Don’t hate me, but I mistakenly removed one of the supply lines and lost the gases. Aside from the gasses that escaped is there anything else to be drained from the system?

A- Would using one of DIY KITS save me money instead of paying the garage to do it?

B- How much should I be paying the garage to 1-INSTALL the AC Compressor? 2- REFILL Freon?

C- Given the system is dry and the compressor is new, WHAT TYPE of FREON REFILL should I use?

D- Is there ANYTHING SPECIAL I should do beyond attaching the "R" refill can and emptying the contents into the system? ANY "R" SPECIFIC DIRECTIONS for refilling i.e. R12 R134

Thanks AC Knowledge Team!!

-Matt (haykoon*aol*com)



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» left by Dan from Tucson AZ (1 year 100 days ago.)

I`m getting ready to convert my 1990 Chevy K15 from R12 to R134. I only have one question from all you automotive pros. After flushing the system is there any amount of PAG oil that needs to be replaced in the evaporator or condenser?

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» left by Anonymous (1 year 94 days ago.)

Well, I was hoping to learn about getting my AC up and running in my 90 Buick LeSabre, but I think I'll just put up with the heat. It's only hot for about three months anyway. After reading all of these comments I would say that paying the $400(which is an outrageous price for a little can) for the R-12 would work better than spending $1000 or converting and everything else. My car isn't worth either fix so I'll just deal with it.

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» left by Anonymous (1 year 80 days ago.)

Haven't any of you guys heard of hydrocarbon refrigerants? Work better, provides great cooling faster, cost less, much lower pressure, and compatible with all systems? And they don't add to global warming or ozone depletion! Do the right thing by your kids and Google up Duracool or Hychill or any of the other manufacturers - and don't believe the fluorolobby hype that there is any risk of fire, HCs are in use all over the world and there simply aren't any bodies...

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» left by Jimbo from UK (1 year 22 days ago.)

Well, this post is well over 2 years old. So R134 is now also old hat and there are other substitutes around. The basic problem with AC conversions is that any good mechanic will want you to change everything (compressor, condenser, filter, and any flexible hoses too) so that he can make some good money out of you, and the COST is what most people are seeking to avoid. The truth is you don't need to replace anything if you don't have a leak and your AC is working fine, just LEAVE it alone and if it's R12 SELL THE CAR, it's TOO OLD already! If you do have a leak, with either type of gas, then if it's slow (i.e. takes a couple of months to stop cooling) then just keep topping it up with whatever is in it already. If it's a faster leak, SELL THE GODDAM CAR! If you REALLY want to give this a go out of curiosity, then get a conversion kit and read the instructions, then follow them - check those against this guy's instructions, and leave a bit of leeway in case the instructions on the conversion can are relevant only to the use of the can! If you don't want to risk damaging your car but you do have AC problems - SELL IT! If you have a non-working AC or one with a leak, DON'T CONVERT IT, because doing the conversion won't fix your problems! For goodness' sakes, use some COMMON SENSE and stop offending each other, plebs!

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» left by jpe (173 days 5 hours ago.)

this last comment was dumb

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» left by Anonymous (119 days 16 hours ago.)

Jimbo, thanks for insulting nearly every honest working american who can't quite afford a socialist-subsidized auto, like you probably drive. Some of us actually take pride in keeping our $2000 pickups running past 60,000 miles and saving some of our hard earned money that Obama and his minions haven't been able to steal from taxpayers, yet. if you don't agree with fixing A/C on an older model car, why the hell did you come onto this page in the first place?!!

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» left by Offender (99 days 5 hours ago.)

I like this part: "For goodness' sakes, use some COMMON SENSE and stop offending each other, plebs!"

 

Just after he tells us we're all idiots for trying to save money by not buying a new car every 5 years. Common sense indeed.

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» left by ian from uk (88 days 17 hours ago.)

the cheapest and in my eyes the best way is to replace the cfc's in you a/c system that has lost gas is to replace it with hcfc's

 

ie i used regular bbq propane and butane mixed, you use approx half the amount of the regular refigerant that was in it!!! if it leaks it has zero afect on ozone, does not need to have the oil changed and is in plentifull supply!

 

the only side that scares ppl is the fact it is flammable, but what you are not told is that normal refigerant when mixed with the oil in the system and is under pressure, if this leaks this 2 is flammable!

 

the olny things needed really are the tools to get the gas into the system!

 

again these can end up costing more than just getting it done professionally!

 

i feel quite happy running around in my car with propane in! and even though the condenser is at the very front of the car and is the 1st thing to be hit in an accident it does not bother me!

 

we tested what might happen with a loose hose and car running on an old car i had! all that happened is 1 small cloud of gas as it escaped in a hurry!!!

 

look for hycilll minus 30 this is a product out there for car a/c that is just propane and butane mixed! sold for this purpose!!!

 

i highly reccomend it :)

 

ian

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» left by Anonymous (86 days 16 hours ago.)

VERY HELPFUL  IN A LANGUAGE YOU CAN UNDER STAND

THANK YOU

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» left by john smith from houston,tex. (80 days 7 hours ago.)

You don't turn the can upside down, that ruins the compressor. The compressor only pumps a gas not the liquid. If you want to get all the refrigerant from the can shake it or place it in some warm water to evaporate the rest of the liquid into a gas state.

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