Added Freon to AC system with can upside down, how to fix?

I’ve been in this business for almost 30 years and most people I know call it freon. I’m not saying it’s right but freon has become the catch all word for R12 or R134.

I charged my system on my Suburban yesterday and when I went to a parts store I asked for R134 refrigerant, the guy at the counter states he’s got freon for X$ amount per can and brings out the 3 cans of 134 that I need.

Every tech I work with calls it freon but we all know that we are referring to R134.

If you intend to buy equipment to service air conditioning systems, I cannot recommend this investment unless you legitimately have the skills to use them, and own a shop that services automotive a/c systems. Most shops use automated machines which open and close the valves at the appropriate times when charging the system to ensure an accurate charge. These machines usually cost a couple thousand dollars for a basic one. Alternatively, you can use a set of manifold gauges, a deep vacuum pump intended for a/c service (necessary to evacuate the system), and a calibrated digital scale to measure how much refrigerant is going into the system. This route would be more challenging and less accurate than an a/c machine, but would be cheaper. You would probably have a little under a thousand dollars into equipment going this route. It will probably be cheaper and better to just have this work done by a professional as required.

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Oh no, the refrigerant is already in the system, theres no problem there. You dont need to have it evacuated and recharged. I was just refering to the dangers of introducing refrigerant in its liquid form into the low side of the system. Only under certain circumstances can you introduce refrigerant in its liquid form into a refrigeration system. I’m not trying to be funny here but I have always been against unqualified persons servicing any kind of air conditioning or refrigeration systems. Its just too dangerous and the unqualified individual could seriously injure or kill themselves or a bystander. I have known professionals to make mistakes and severly injure themselves. A/C systems are nothing to play with. Its all too common especially this time of year for someone to go into an auto parts store and tell the guy at the counter “Hey my A/c is not cooling” The first word out of their mouths is “Here, throw a can of refrigerant in it” So thats what a majority of people do. They grab a can and that pretty blue adaptor hose and go to town. Not knowing thing one about refrigeration. Something else could be wrong with the system and adding that can of refrigerant could cause a disaster. I have worked on both auto and commercial refrigeration and have seen people get hurt. You can have all the equipment in the world but if you dont understand an A/C or refrigeration system, those things wont make much sense. I really would just let a pro check it out for you. It could be something as simple as a cooling fan not operating causing excessive head pressure and cutting the system off.


SUVA is the DuPont trade name for refrigerant R-134a.

Just because everyone else is ignorant when calling it Freon, doesn’t somehow make it right. Kind of like when Bush kept saying “nuke-u-ler” for “nuclear” and now it has become an accepted pronunciation for the word… which just makes me sad inside.

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I once DIY recharged my old '87 Accord and I am still here, but it wasn’t a pleasant experience. I was young(er) and dumb.

My '99 Accord that I drive now started to cool poorly last spring so I took it to a shop. One thing they have that you probably don’t have is equipment to detect leaks, and also a set of gauges with the high side, too.

It was $90 well spent and now over a year later the system still cools to 40?

Transman gave you some pretty solid advice, leave this work up to someone who has worked on A/Cs before.

Take your vehicle to someone that knows what they are doing.In my 37 years of experience I can’t believe how many mechanics don’t know the fundamentals of an A/C system.Both High and Low pressures must be observed.Your fan must work well. The condenser should be cleaned with a water hose to remove dirt and bugs.The proper refridgerant oil and amount should be adhered to.A vacuum should be put on the system for 20 minutes.The charging port valves should be changed at servicing-always. Don’t use stop-leak for an A/C system.Put the factory recommended amount of refridgerant. If you are charging the system on a very hot day, put a fan in front of the vehicle to cool down the condenser, simulating air flow while driving.

The '94 Grand Cherokees use 134 so the regular Cherokees most likely do too.

I have heard slugged compressors, did not sound good but they still cooled after the noise went away.

Adding refrigerant to a system as a liquid could damage the valves on the compressor but it is unlikely that it did. Freon is a Dupont trademark for R12 If your car is a 1994 or newer it should take R134a. The service valve for charging is on the low side, the side that has the largest diameter tubing or hoses. Also when charging you need to keep the lines clean and free of air. If the system was empty you would need More than one can. Check to be sure the compressor clutch is engaged and the condenser fan is running. A fully charged system should produce sweat on the low pressure line and produce heat on the high side. If you get these results and the car doesn’t cool, check the blend door or heater control valve. When in doubt leave it to an expert

I am strictly an amateur, but 5 out of the six times I have charged an a/c system it worked fine and 4 of those times it lasted the whole season. The cost of taking an old car to an a/c shop is prohibitive. The one car I took to an a/c shop, they recharged and tested it and told me it was ok and didn’t leak. Three days later the refrigerant was all gone. When I went back and complained they offered to apply they cost of the recharge to the repair, then gave me an estimate for over $1000.00

My AC repair, start to finish.
The AC was blowing cool but not cold air so I added a can of R134a and it immediately got very cold. It did not last. At first I thought that I messed things up because I held the can with the fill hose on the bottom so that liquid was going into the system instead of gas, but that did not seem to cause a problem. The R134a that I added had a dye in it to help find any leaks but I could not see any dye glowing so I took it to CarX and made it clear to them, specifically, that all I wanted them to do was find the leak. They also added more dye but could not find the leak; they wanted to charge me $136 dollars for not finding the leak that I was paying them to find. After telling them the idea of paying for not finding what I was paying them to find was absurd, they said, ok, no charge. When I got home I noticed R134a bubbling and hissing and leaking from the condenser, front and center of the car. Funny that CarX did not see this, even though I had removed the front grill before taking the car there and the condenser was exposed in plain sight.
I managed to get a condenser at wholesale price, $70, but then I could not get the top nut loose and I twisted the hose tubing so I ordered a hose from, which cost $36 and I had to wait 5 days for delivery. To get the lower nut loose without breaking it like the top one, I heated it with MAPP gas, just a little heat and it loosened right up. I put a heat protection cloth behind it to shield the radiator from damage. When I was installing the new condenser I realized that the threads on the lower hose were stripped from the previous installation and it would not go on so I bought a new lower hose. This time, I checked with AutoZone and even though they had to order the hose, they had it the next day for the same price as jeepair, $36. The hoses came with O-rings so don?t buy a pack of O-rings if you don?t need to. Also, the guy at jeepair said not to put any thread sealant stuff on the threads. After installing the new condenser and hoses I drove over to CarX and they put a vacuum on the system and said that was supposed to sit for 30 minutes with the vacuum on. They checked that the vacuum held so there were no leaks and then added R134a; I think it was two pounds. CarX has a $40 deal to ?check? your AC system; this is basically to get you in the door, then the charges start adding up. They charged me $140 to vacuum the system and add the R134a, it seemed excessive to me.
All is working well, very cold air.
condenser $70
hose $36
hose $36
vac and charge $140

total $282

Thats great but one question. Who evacuated and recovered the refrigerant from the system BEFORE you started the condenser replacement?? You cant just release refrigerant into the air, thats a federal offense. It must be recovered using special refrigerant recovery equipment.

It looked like you saved a few bucks by performing most of the labor by yourself.


When this all first started, I took it to CarX to check it and they must have added some R134a because something was bubbing and hissing from the condenser when I got home (less than a 1/4 mile). Whatever was in the system leaked out the hole in the condenser. I assumed that if I went back to CarX they would not have been able to evacuate the system since it had the hole in the condenser. I saved a few bucks. I learned a lot. Have a new respect for AC technicians.

Ikr? And Jimmy Carter said it long before that.

It would be interesting if to see if accidents were reduced by them charging the person driving for a federal crime when found at fault [if their [or the another vehicle’s] AC evacuates).