Thermostatic Expansion Valve
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
An in-line filter is installed in the auxiliary evaporator inlet line at the floorpan bracket connection. A restriction in this filter may cause misdiagnosis of a failed thermostatic expansion valve. This filter must be inspected before a new thermostatic expansion valve is installed.
NOTE:
Install a new evaporator core orifice and thermostatic expansion valve in-line filter whenever a new A/C compressor is installed.
The thermostatic expansion valve (TXV) restricts the flow of refrigerant from the high pressure side of the refrigerant system and separates the low pressure and high pressure sides of the auxiliary refrigerant system. Refrigerant entering the auxiliary evaporator core passes through the TXV. A temperature sensing bulb senses the temperature of the refrigerant flowing out of the evaporator core and adjusts an internal pin-type valve to meter the refrigerant flow into the evaporator core. The internal pin-type valve decreases the amount of refrigerant entering the evaporator core at lower temperatures and increases the amount of refrigerant entering the evaporator core at higher temperatures.