
Como recarregar o ar condicionado do carro
Remember, the basic logic of charging refrigerants is to detect leaks first, vacuum air second, and charge last.
Leak Detection
Before charging, inspect the car’s air conditioning system for leaks. Repair them immediately if any leaks are found. Otherwise, the system will lose refrigerant even after recharging.
Vacuum the System
If there are no leaks, proceed to vacuum the air conditioning system as follows:
Connect the Manifold Gauge
Connect the high-pressure side of the manifold gauge to the system’s high-pressure port (Red ). And the low-pressure side to the low-pressure port(Blue).

Connect the Vacuum Pump
Connect the center charging hose of the manifold gauge to the vacuum pump inlet. Open both low- and high-pressure manifold gauge valves and start the vacuum pump. Vacuum the system for 15-30 minutes until a deep vacuum is achieved (below -0.1MPa or lower).

Pressure Holding Test
Close the manifold T-port and manifold valves, then wait 10 minutes. If the pressure rises, the system has leaks. If the pressure remains stable, the system is well-sealed and ready for refrigerant charging.
Two Ways to Recharge Refrigerants
Refrigerants can be recharged through either the high-pressure side or the low-pressure side.
| Aspect |
High-Pressure Side |
Low-Pressure Side |
| Pressure |
High |
Low |
| Safety |
High risk; improper operation can damage the compressor |
Safe and easy to control |
| Charging Speed |
Fast |
Slow |
| Precisão |
Difficult to control precisely |
Easy to control the exact charge |
| Suitable Scenario |
Professional repair, liquid refrigerant recovery |
Routine charging, beginners |
High-Pressure Side Charging
- Wear protective gloves and glasses.
- Place the refrigerant cylinder upside down (liquid charging) and connect the high-pressure side hose of the manifold gauge to the cylinder charging valve. Ensure the low-pressure hand valve is closed, and the system has no abnormal pressure.
- Open the cylinder valve and the T-port and high-pressure hand valve to allow refrigerant to flow slowly into the system. The engine must remain off to avoid compressor damage.
- After initial charging, close the high-pressure hand valve, start the engine and AC, set the blower to maximum airflow and temperature to minimum, and run for 5–8 minutes to circulate the refrigerant.
- Open the high-pressure hand valve again and continue charging according to the manifold gauge reading or manufacturer’s recommended refrigerant amount until the system reaches the specified pressure or weight.
- Close the high-pressure hand valve and cylinder valve, then check the system pressure and cooling performance to ensure there are no leaks.
Low-Pressure Side Charging
- Wear protective gloves and glasses.
- Place the refrigerant cylinder upright and connect the low-pressure side hose to the cylinder charging valve. Ensure the high-pressure hand valve is closed.
- Open the cylinder valve, the T-port, and the low-pressure hand valve, allowing refrigerant to flow slowly into the system. Observe the manifold gauge and charge initially to about 0.4 MPa.
- Close the low-pressure hand valve, start the engine and AC, set the blower to maximum airflow and temperature to minimum, and run for 8 minutes to circulate refrigerant fully.
- Open the low-pressure hand valve again and continue charging according to the manifold gauge reading or manufacturer’s recommended refrigerant amount until the system reaches the specified pressure or weight.
Safety Tips
- Always wear gloves and protective eyewear.
- Low-pressure side charging is recommended for routine maintenance due to safety and control.
- High-pressure side charging should only be done by professionals.
Considerações finais
Recharging your car’s AC is a straightforward process when done correctly. By following this guide, you can save money on mechanic fees and keep your vehicle’s air conditioning running efficiently. However, if your AC system has ongoing issues, such as frequent refrigerant loss, professional repair may be necessary.
Now that you know how to recharge car AC, you can enjoy a cool and comfortable ride all summer long!
For high-quality AC recharge kits and auto air conditioning components, check out ACTECmax, um fornecedor confiável de soluções de ar condicionado automotivo mundialmente.