Buick 13313727 Expansion Valve

There are multiple 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 it, ultimately cooling the airflow for delivery through the vents. Typically, this conversion is achieved through a sudden change in tubing size. In some vehicles, there is a removable controlled orifice in one of the refrigerant lines at the firewall. However, certain models utilize an A/C Expansion Valve to accomplish the same function 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. Afterward, the refrigerant lines can be disconnected from the A/C Expansion Valve at the firewall, followed by the removal of the valve by unscrewing the two bolts securing it. Finally, the valve can be replaced along with the four O-rings. The installation process is the reverse of the removal procedure.