Air Conditioner Refrigerant Charge Loss

Possible causes

• CommonSlow leak at a hose, seal or connection
• CommonLeaking condenser, often from stone damage at the front of the car
• CommonLeaking compressor shaft seal
• CommonNatural loss over many years without servicing
• PossibleLeaking evaporator inside the dashboard
• PossibleFaulty pressure sensor reporting low charge that is not real

What you might notice

• Air conditioning blowing warm
• Compressor not engaging
• Cooling gradually getting worse over months
• Oily residue near a pipe or the condenser
• Check engine light on

What to check, in order

1. Have the system tested for leaks properly rather than simply recharged. A recharge without a repair is money spent on refrigerant that will escape again.
2. Look at the condenser at the front of the car for stone damage and corrosion - it is the most exposed part of the system.
3. Look for oily residue around pipe joints. Refrigerant carries oil, so a leak leaves a mark.
4. Do not run the air conditioning with a known low charge. The compressor is lubricated by oil carried in the refrigerant, and running it dry is what turns a leak into a compressor.
5. Run the air conditioning briefly every few weeks even in winter. It keeps the seals lubricated and is the cheapest way to avoid the next leak.