How do I Know if my AC Needs Recharged?

“How do I know if my AC needs Recharged?” Welcome to Mercie J Auto Care, Where Compassion and Craftsmanship Come Together. I'm Rick Smith, ASE Certified Master Technician. The primary way to determine if an air conditioning system needs to be charged is with two pressure gauges. We have a high pressure side of the system and a low pressure side. If the system is not cooling as it should and both gauges read low, that’s a very good indication they system is low. Once we have identified any leaks, then we recover the refrigerant. You may have heard it called “freon”, but that is a generic brand name. The refrigerant is a greenhouse gas, so we don’t release it into the atmosphere, we recover it. With no refrigerant in the system we make any repairs such as a hose, compressor, or expansion valve replacement. Once the repairs are made, we evacuate the system. We only want refrigerant, oil, and a small amount of dye in the system. By evacuating or putting the system under a vacuum, we remove air and other contaminates. Depending on the depth of the repair, we will evacuate typically anywhere from 10 minutes to 45 minutes. Once the evacuation is complete, we charge the system with refrigerant. If we try to charge it by the pressure readings, we will not be accurate. Slightly too much and we can damage the compressor. Slightly too little and we can damage the compressor. We charge the system with a precision scale. There is a weight specification for each vehicle which will give us the right amount of refrigerant for optimal operation.