Q: How to Remove and Replace the Expansion Valve in an Automotive Air Conditioning System?
A: To remove and replace the expansion valve in an automotive air conditioning system, follow these steps: First, have the air conditioning system discharged by a technician. Then, disconnect the cable from the negative battery terminal, making sure to disconnect the Intelligent Battery Sensor (IBS) connector first if applicable. Next, remove the bracket securing the refrigerant lines to the left shock tower. Disconnect the refrigerant lines at the firewall by removing the nut that secures the line fitting to the expansion valve, and cap or plug the line openings to prevent dirt or moisture from entering. Remove the two mounting screws that secure the expansion valve, detach it from the evaporator fitting, and discard the O-rings. For installation, use new compatible O-rings and reverse the removal steps. Finally, have the system evacuated, recharged, and leak-tested by the technician who discharged it.