How to Check if the Car Air Conditioning Refrigerant is Sufficient?

[Tobias]

Here are the methods to check if the car air conditioning refrigerant is sufficient: 1. Observation Method. This method involves observing the bubbles in the refrigerant through the sight glass to determine if the refrigerant is sufficient. The sight glass is usually located on the dryer's cap. After locating the sight glass, clean it and follow the steps below for inspection. (1) Start the engine, maintain its speed at around 2000r/min, and activate the air conditioning system. Then observe the refrigerant flow through the sight glass. If the refrigerant level in the air conditioning system is appropriate, you should see clear refrigerant flowing continuously without bubbles, except for occasional small bubbles at high temperatures. (2) Alternately turn the air conditioner on and off to confirm whether you are truly seeing clear refrigerant. Since the refrigerant is transparent and colorless, if it has all leaked out, it might be mistakenly assumed that the system is full of refrigerant. Turn off the air conditioning system and observe the sight glass. If there is refrigerant in the system, small bubbles should be visible when the system is off. If no small bubbles are seen during operation and the system is cooling the car, everything is normal. (3) If small bubbles are visible in the sight glass during operation, it indicates insufficient refrigerant. A professional should be consulted promptly for inspection and repair to identify the leak. (4) If a streak of oil or occasional chunks of oil are seen in the sight glass during operation, it indicates partial refrigerant leakage. The refrigeration system should be inspected and repaired by a professional immediately. 2. Temperature Method. This method involves checking the temperature at the dryer's inlet and outlet to determine if the refrigerant charge is appropriate. (1) First, locate the dryer in the air conditioning system. The dryer is usually positioned in front of the condenser, resembling a fire extinguisher (cylindrical), with two pipes connected to it—one leading to the expansion valve and the other to the condenser. (2) Run the engine at around 2000r/min and activate the air conditioning system. Hold both pipes with your hands to feel the temperature difference. (3) If the temperatures of both pipes feel similar, the refrigerant charge is appropriate. If the pipe leading to the condenser feels colder, it indicates insufficient refrigerant in the system. A professional should be consulted immediately to check for leaks in the refrigeration system.