How to Add Refrigerant?
2 Answers
There are two methods for adding refrigerant, but the procedures differ depending on the state of the refrigerant: 1. Liquid refrigerant must only be added through the high-pressure side, which is safer and faster, making it suitable for initial filling after evacuation. Note that liquid refrigerant must be added in an inverted position. 2. Gaseous refrigerant must be added through the low-pressure side. Due to its slower filling speed, this method is suitable for supplemental filling. Methods to determine if your car needs refrigerant oil: 1. If the air conditioning reaches the set temperature quickly after normal operation for a period of time, it indicates normal conditions; otherwise, refrigerant oil needs to be added. 2. Measure the temperature difference between the air inlet and outlet of the indoor unit with a thermometer. If the difference is below approximately 8°C, refrigerant oil needs to be added.
DIY refrigerant charging is actually quite fun. I started trying it many years ago and now I'm quite familiar with the process. First, you need to buy a dedicated charging tool kit, which includes charging hoses, a pressure gauge, and refrigerant cans. The first step is to locate the low-pressure charging port of the A/C system—usually under a cap marked with an "L" on the left side of the engine bay. Open it and connect the charging hose adapter. Then shake the refrigerant can for at least 30 seconds to mix the contents evenly. After putting on goggles and gloves, slowly open the valve to start charging; the pressure gauge will display readings, with normal low pressure typically between 25 to 45 psi. During the process, inject the refrigerant slowly to avoid overcharging, which can damage the compressor. After charging, run the A/C for 5 minutes to test the cooling effect—if the air isn't cold enough or the pressure fluctuates significantly, there might be a leak requiring professional repair. Safety is the top priority—improper handling under high system pressure can harm your skin, so beginners should be cautious, as saving money is secondary. Regularly checking the A/C lines can reduce the frequency of refrigerant top-ups.
