What is the reason for the car AC losing pressure after a few days of use despite holding pressure during testing?
2 Answers
First, it's necessary to determine whether there is a refrigerant shortage. Another possibility could be leakage at the charging port. If refrigerant is present but cooling isn't functioning, it might be due to poor electrical connection. Here's an introduction to car AC systems: 1. Overview: A car air conditioning system refers to the climate control device installed in vehicles, capable of cooling, heating, ventilating, and purifying cabin air to provide passengers with a comfortable environment, reduce driver fatigue, and improve driving safety. 2. Structure: Typically includes refrigeration units, heating units, and ventilation systems. This integrated design maximizes the limited interior space of vehicles with simple structure and easy operation, representing the internationally prevalent modern automotive AC system. 3. Configuration: Different types of AC systems have varying layouts. Currently, integrated heating-cooling systems are widely adopted in passenger cars. The typical arrangement combines evaporator, heater core, centrifugal blower, and control mechanisms into a single assembly called the AC unit.
I've been driving for over twenty years and have encountered situations where the AC held pressure during a leak test but lost cooling after a few days on several occasions. In fact, pressure testing isn't foolproof—tiny leaks may go unnoticed under constant pressure, but road vibrations or temperature fluctuations can enlarge them, such as aging seals or loose connections, leading to gradual refrigerant loss. Environmental factors also play a role; refrigerant expansion during hot weather increases leakage risks. From my experience, adding fluorescent dye and checking for leaks after a few days of driving yields better results. Additionally, regular maintenance is crucial, especially for vehicles over five years old—I recommend inspecting the AC system and cleaning pipeline dust every six months. Prevention is far more cost-effective than repairs; a failed compressor is a much bigger headache. Always keep the interior clean to prevent debris from blocking air vents.
