Ford 7T4Z-19849-A Expansion Valve

There are several ways that air conditioning systems convert the high-pressure liquid refrigerant from the compressor to the air conditioning evaporator. The evaporator is chilled as the refrigerant passes through, cooling the airflow through the evaporator for delivery to the vents. The conversion is usually accomplished by a sudden change in the tubing size. Many vehicles have a removable controlled orifice in one of the AC pipes at the firewall. The models covered by use a thermostatic expansion valve (TXV) that accomplishes the same purpose as a controlled orifice. To remove the TXV, have the air conditioning system discharged by a licensed air conditioning technician, then disconnect the refrigerant lines from the TXV at the firewall, remove the two bolts securing the valve, then remove the valve.