When hot summer days come around, having your car’s air conditioning system up and running at maximum efficiency can be a life-saver. Nobody likes being stuck in traffic drenched in his own sweat because the AC is only blowing hot air. It’s like being stuck in a sauna against your own will. 

That’s why in spring, you’ll want to check if the AC is in working condition and recharge it if needed. While this is best done by a certified mechanic during your regular spring car maintenance, you can still do it on your own. Today, we are going to cover how to perform an AC recharge by yourself in a few easy steps.

Step-By-Step Guide on How to Recharge Your Car’s AC

  1. Since the air conditioning system in your car is airtight, the only way it can be low on refrigerant is if there is a leak somewhere. Instead of going out of your way in finding this leak, we recommend using a refrigerant that contains a sealant in the formula. This will help temporarily alleviate the problem and will save you money for the time being. You’ll also want to have a dispenser with a pressure gauge and a trigger. 
  2. Diagnose the problem by observing the AC’s compressor and testing the pressure. Before you get down to business, make sure you have the necessary safety equipment. We recommend using safety goggles and a pair of gloves when handling a dangerous liquid like refrigerant.Turn the ignition on and crank the AC to the max setting. Now locate the clutch of the compressor and check if it’s running. If it’s indeed spinning, proceed to the next step. If the clutch is not spinning or is spinning at a slow speed, the system is either running very low on refrigerant, and the pressure is low, or it is due to a different malfunction. In this case, we advise you to seek out assistance from a mechanic.
  3. In order to conduct the car AC recharge properly,  you’ll have to test the pressure level first. To do this, you’ll need to locate the low-pressure port. On most vehicles, it should be located somewhere on the left side of the engine bay. You can also find it by following the air conditioning lines. Follow the larger of the two, and you’ll have no problems finding the port. At this point, you’ll want to take the dispenser and attach it to the port. Make sure it’s properly secured on the fill port.
  4. While your engine is running and your AC is set to the max settings, monitor the pressure gauge readings. You’ll notice different colored zones that indicate if it’s safe to proceed with the AC recharge. If the needle is in the white or green zone, you’re good to go. On the inside of the gauge, you’ll notice numbers indicating various temperatures. These numbers correlate to the current outside temperature. To determine the acceptable pressure range, take your mobile phone and check the exact outside temperature. Once you’ve figured out the target pressure range, proceed to fill the system with refrigerant.
  5. Install the dispenser onto the can by following the included instructions. Shake the can before use and connect the dispenser to the low-pressure port once again. Proceed to squeeze the trigger in five to 10-second intervals, while also tipping the can from side to side. Avoid turning it upside down. Let go of the trigger and check the pressure readings to make sure you’re not overfilling the system. Repeat until the gauge needle reaches the target pressure range. 
  6. Once you’re done, disconnect the dispenser from the pressure port and don’t forget to screw the cap back on. Conduct a final test by examining the temperature of the air blowing from the vents. It should be somewhere between 30 and 45 °F.


This concludes our guide on how to recharge air conditioner systems in cars and trucks. If you’re not happy with the results or you don’t feel comfortable dealing with air pressure and refrigerant, we highly recommend taking your car to the nearest workshop and consulting a professional technician. For more advice on how to maintain your vehicle by yourself, feel free to browse through our blog section.