How to Locate the Low Pressure Port in a 2003 Chevy Impala

by Kyle Sanstrom

The low-pressure port in a 2003 Chevrolet Impala is the port where refrigerant is added to the air-conditioning system. This port is TIG-welded to the top of the aluminum low-pressure line and covered with a blue plastic dust cap. The dust cap prevents dirt and contaminants from interfering with the low-pressure port valve. It also prevents something from accidentally depressing the valve stem and inadvertently evacuating refrigerant into the air. Refrigerant must be recovered and evacuated by a licensed facility and never released, accidentally or purposely, into the atmosphere.

Step 1

Shift the transmission into park, apply the parking brake and open the hood.

Step 2

Stand in front of the engine, looking toward the windshield. Look straight down and locate the two aluminum lines coming off the right side of the air-conditioning condenser.

Step 3

Look at the large diameter line; this is the low pressure line. Follow this line back toward the firewall approximately 12 inches. The low-pressure port is covered with a blue or sometimes black cap with an “L” stamped on top.

Unscrew the cap to expose the low-pressure port.


  • Sometimes the dust cap may be missing and you won’t be able to use this as a means of identifying the low-pressure port. Just remember: The low pressure port always is mounted on the larger-diameter tube. Compare the two tubes coming off the air-conditioning condenser and follow the larger tube away from the condenser toward the firewall until you run into the low-pressure port.

Items you will need

  • Work light

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