There are various methods for converting high-pressure liquid refrigerant to lower pressure vapor in air conditioning systems. This conversion occurs at the air conditioning evaporator, which is cooled as the refrigerant passes through, ultimately cooling the airflow for delivery through the vents. Typically, this conversion is achieved through a sudden change in tubing size, while some vehicles may have a removable controlled orifice in one of the AC pipes at the firewall. However, the models I use employ an A/C expansion valve that serves the same purpose as a controlled orifice. To remove the A/C expansion valve, it is necessary to have the air conditioning system discharged by a licensed technician. After discharging, the evaporator core can be removed, and the refrigerant lines disconnected from the A/C expansion valve. The valve can then be removed by taking out the two securing bolts. The installation process is the reverse of removal. Finally, it is important to have the system evacuated, recharged, and leak tested by the same shop that discharged it.