How to Recharge Car AC
Learn how to recharge car ac with our detailed step-by-step guide. Follow our easy instructions to get it done right.
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0 of 6 steps completedStep-by-Step Instructions
1 Step 1: Verify AC System is Low on Refrigerant
Step 1: Verify AC System is Low on Refrigerant
Check if AC blows warm, compressor doesn't engage, or low-pressure reading indicates low refrigerant.
AC Pressure Gauge Set
Manifold gauges for checking AC system pressure
2 Step 2: Locate Low-Pressure AC Port
Step 2: Locate Low-Pressure AC Port
Find low-side service port (larger of two ports, usually near AC accumulator or firewall).
AC Service Port Cap Set
Replacement caps for AC service ports
3 Step 3: Connect Recharge Kit to Low-Pressure Port
Step 3: Connect Recharge Kit to Low-Pressure Port
Remove port cap, attach recharge hose with gauge to low-pressure port until it clicks.
R-134a Recharge Kit
AC refrigerant with hose and gauge for recharging
4 Step 4: Start Engine and Turn AC to Max
Step 4: Start Engine and Turn AC to Max
Start car, set AC to maximum cold and highest fan speed, verify compressor engages.
5 Step 5: Add Refrigerant While Monitoring Pressure
Step 5: Add Refrigerant While Monitoring Pressure
Squeeze trigger in short bursts, watch gauge, fill to 40-45 PSI on low side (do not overfill).
Extra R-134a Refrigerant Can
Additional refrigerant if system needs more than one can
6 Step 6: Check for Leaks and Test Cooling
Step 6: Check for Leaks and Test Cooling
Feel vents for cold air (should be 40-50°F), check for leaks with UV dye if included.
AC Leak Detection Kit
UV dye and light for finding AC system leaks
Infrared Thermometer
Temp gun for measuring vent temperature