How To Check Your A/C System

How To Check Your A/C System

Summer will be here before you know it.


What most people don’t realize is that over time, an automotive A/C system can, and will, leak refrigerant. When you are driving, your auto A/C experiences vibration, bumping and extreme temperature changes. This causes parts inside the system to loosen and allows gaskets and O-rings to shrink over time, which allows refrigerant to escape (or leak). Once the system loses refrigerant, it will lead to the vehicle blowing warm air, requiring a recharge.


Using a do-it-yourself recharge product allows you to put refrigerant back into the system and saves you money by avoiding a trip to the mechanic.

  1. Start your engine and turn your A/C on max with the fan on high.
  2. Confirm your compressor is on.
  3. Locate the low-pressure service port.

There are typically two ports that allow access to a vehicle’s A/C system.

  1. There is a low-pressure port located on the larger-diameter (or thicker) line that runs from the compressor back toward the firewall (toward the windshield). This is the port you use to recharge.
  2. The high-pressure port is located on the narrower diameter (or skinny) line that runs forward from the compressor toward the front of the car, where the condenser is located.
  3. Remove the shipping disk from the canister.
  4. Attach the quick-connect fitting on the end of the recharge hose to the low-pressure port by simply pushing it on.
  5. Check the gauge pressure when the compressor cycles on. Rotate the black dial so that the blue arrow on the gauge face points to the current ambient (outside) temperature on the dial. Disconnect the gauge from the low-pressure port.
  6. Shake the can well. Screw the can into the hose assembly and reconnect the quick connect to the low-pressure port. Squeeze the trigger on the charging device to begin charging.
  7. Refer to the specific charging instructions on the product for more details.

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