How to Check if the Car Air Conditioner Refrigerant is Low
2 Answers
To check if the car air conditioner refrigerant is low, follow these methods: 1. When the air conditioner is running normally and continuously, if there are continuous bubbles in the sight glass, it indicates insufficient refrigerant; 2. When the air conditioner is running normally and continuously, if there are no bubbles in the sight glass, but brief bubbles appear when the air conditioner stops, it indicates the refrigerant level is normal. The process of refilling the air conditioner refrigerant is as follows: 1. Evacuate the system, close the manual valves on the pressure gauge and the high and low pressure manual valves; 2. Connect one end of the hose to the injection valve fitting of the refrigerant can; 3. Open the refrigerant can, loosen the nut on the pressure gauge hose to let some gas escape, then close it; 4. Open the high-pressure side manual valve and invert the can; 5. Inject the specified amount of liquid refrigerant, then close the refrigerant injection valve and the high-pressure manual valve.
Having driven for many years, I've learned several telltale signs to check when the car's air conditioning refrigerant is low. First, start the engine, turn the AC to the coldest setting, and wait a few minutes to feel the temperature from the vents. If it's not cool enough or even blows warm air, it's likely low on refrigerant. Second, listen to the compressor sound—it should run smoothly when functioning normally. If refrigerant is low, the compressor will frequently cycle on and off, making clicking noises, sometimes accompanied by pipe frosting, especially when the low-pressure pipe feels icy or even frosty. Additionally, many cars have a sight glass on the piping—pop the hood and check. A clear view with no bubbles means sufficient refrigerant, while excessive bubbles indicate a shortage. I've encountered this issue a few times, and during one visit to the repair shop, they found a leak point. The mechanic replaced the refrigerant, and the system returned to normal. I recommend checking the AC system every six months to avoid prolonged poor cooling, which can strain the engine. Remember, these small checks can save trouble, but if there's a real issue, always seek professional help.
