DIY: How to Recharge Your Cars Air Conditioner
Many of us holding on to older cars, or the few that are unlucky with newer vehicles, find ourselves needing yearly Freon shots to get through the hot summers. Mechanics prices vary greatly when servicing your air conditioner, but it’s not unheard of to pay $100-250 for an a/c charge. The cost to do this simple procedure yourself is around $25. Please don’t let anything scare you about charging your car’s a/c yourself, it’s really quite simple. Anyone can accomplish this cost and comfort saving task, hopefully the following steps will guide you through the process.
Step 1 – Purchase Refrigerant and Gauge. The main reason people are scared to charge the car’s a/c is because it’s known that you need to be licensed to handle Freon. This is true, however, 1995 and newer passenger cars and trucks take a kind of Freon called R134A, which does NOT require a license to use. Almost every auto store will carry R134A Freon and just last weekend I saw it pretty cheap at Wal-Mart ($10-15). Typically, one can is enough to completely charge your system unless it is empty, which might take two. When purchasing the Freon, make sure you buy a can that comes with a gauge. This gauge will measure the pressure in your a/c system and makes refilling the refrigerant to the correct pressure a breeze. This gauge is reusable and will only require you to purchase cans for future fillings. The following pictures are all different products that will work.
Step 2 – Locate the Low Side Fitting Under the Hood. Don’t let this kind of language discourage you, the low side fittings is easy to locate and the picture provided should help. Air conditioners have two sides on them a low side and a high side. The Freon has to be filled through the low side fitting. Usually, your vehicle will have an “L” label on the low side cap and an “H” on the high side cap. The nozzle that will attached to the low port does not physically fit on the high side port, so don’t get too worried about doing this wrong. You will have to unscrew the dust cap in order to put on the gauge.
Picture of Low Side Fitting Port – Usually Blue and labeled “L”
Step 3 – Attach Gauge and Refrigerant to Low Side Port. Once you have located the proper port, it’s time to connect the can of Freon and gauge. While the car is off, pull up on the gauge nozzle and press it down gently onto the port, you will know it is on correctly when you wiggle the gauge and it stays on securely. Next, attached the can of Freon to your gauge, depending on the type of can and gauge you have, you usually turn the can into the threads until it is tight—this will puncture the can. Once this is connected, do not pull the trigger on the gauge, because this will release the refrigerant.
Your Gauge Should Look Like This When Hooked Up
Step 4 – Start Car and Read the Current Refrigerant Level. Now that everything is attached, go ahead and start your car and turn you’re a/c on full blast (all the way to cold and fans on hi). While your compressor is running, you will see the gauge move. You want your pressure to be right in the middle of the blue gauge setting (settings may vary by gauge, but they are all pretty obvious as to where the correct pressure should be). One tip to reading the gauge is that if you’re a/c is completely out of refrigerant, your compressor will cycle on and off so the it does not burn out. Because of this, you will only be able to get a correct reading while the compressor is on, you will know the compressor turns on when you hear your fans start spinning towards the front of your car behind the radiator. You should also physically hear the compressor turning off and on.
Any Reading in the Green Means You need to Add Refrigerant.
Step 5 – Recharge Refrigerant to Proper Pressure. Locate the trigger or dispenser on your gauge and hold it in, but only when the compressor turns on. Remember, you will likely know by the fans cycling on and off. After holding it in for a few seconds and allowing some refrigerant to enter the vehicle, the compressor will likely stay on because it now has a slight charge. After holding the trigger for a few seconds, stop and take a reading. Keep doing this until the gauge is right in the middle of the proper pressure point. It can take 5-10 minutes to completely drain a can of refrigerant. Be careful not to overcharge your a/c system because this cause damage or failure to your compressor.
Step 6 – Remove Gauge and Put Dust Cap Back On. You are essentially done at this point, all you have to do is release the gauge from the low side port, by reversing the process by which you installed it. Once the gauge is removed, put the dust cap back on. That’s it, you just saved yourself at least a 100 bucks!! If you have any questions, feel free to post them and we will try to help you out. The video below should also help make the process clearer.
Video Showing How to Charge Your Car’s a/c (the gauge is slightly different than what I explained in the post)
Related articles you might be interested in:
If you enjoyed this post, please consider to leave a comment or subscribe to the feed and get future articles delivered to your feed reader or email.
Comments
This is awesome! I have had to take in my 9-year-old car in every single spring to get the A/C system re-charged, without fail. I had no idea it was relatively simple to do it yourself.
Thanks for the tutorial.
To be correct, you would not use the name ‘FREON’ to describe the substance that is injected into the A/C compressor. ‘FREON’ is a tradmark name copyrighted by DuPont. The generic term is ‘REFRIDGERANT’.
The above excercise (recharging of the A/C system) is a quick fix, to be sure. It may or may not last, as it really is a band-aid. There is only one reason why an air conditioning unit needs to be recharged: There is a leak in the system. Leaking A/C units mean refridgerant being released into the atmosphere.
CAUTION should be taken as to the brand of refridgerant that is used. Many of them are propelled by propane. This can be a disaster (and many shops who do A/C repair also have a ‘refriderant identifier’ which will give them the red or green light to proceed with the repair. Depending on the result, the shop may well just tell you to go away. It can be VERY dangerous.
One last note: The gauges that come with these kits are not accurate at all. A look at a shop manual (from the manufacturer) of any given car will indicate EXACT pressures (high side and low side). As much as 1/100th of a pound to much or two little can affect the cooling capabilities of the A/C unit, can mean to much lubricant in the system (or too little) and can cause the leak to worsen and/or the clutch to seize.
Awesome, for several years now I really could have invested in a recharge, but since it wasn’t a necessity, and I’m on the ultra-frugal college budget, it didn’t get done. Instead, I (along with any passengers) suffered through the worst of Iowa’s heat and humidity without decent air!
This is great; never thought of DIY route. Thanks for sharing!
[...] follow up on a recent post describing how to recharge your car’s air conditioner, I’d like to take the issue further and describe the process of charging your home’s air [...]
Cold One, you need to get a life for crying out loud. People like you are the reason that shops think they can charge the earth for simple jobs.
One thing that I question is why you don’t have to “bleed” air out of the filler hose before charging. It seems to me you would be pumping a small amount of air and moisture into the AC line before the refrigerant goes in. I plan on charging my home heat pump. Any comment?
It is very timely post for me as I was looking to get this done for my car.. Was delaying it only because of the cost factor. .. will try to do it myself only now. Thanks !!