Durango 4WD V8-4.7L VIN P Flex Fuel (2007)
Expansion Valve: Description and Operation
Plumbing - Front
Description
DESCRIPTION
NOTE: Typical A/C expansion valve shown.
The A/C expansion valve controls the amount of refrigerant entering the A/C evaporator and is of a thermostatic expansion valve (TXV) design. The
A/C expansion valve consists of an aluminum H-valve type body (1) with an integral thermal sensor (2) and is located at the dash panel between the A/C
refrigerant lines and the A/C evaporator.
Operation
OPERATION
The A/C expansion valve controls the flow of high-pressure, low temperature liquid refrigerant entering the expansion valve and converts it into a
low-pressure, low-temperature mixture of liquid and gas before it enters the A/C evaporator. To meet the vehicles A/C cooling requirements, a
mechanical sensor is used in the A/C expansion valve to monitor the temperature and pressure of the refrigerant leaving the A/C evaporator and then
adjust the inlet port orifice size to allow only the proper amount of refrigerant to enter the evaporator. Controlling the refrigerant flow through the A/C
evaporator ensures that none of the refrigerant leaving the evaporator is still in a liquid state, which could damage the A/C compressor.
NOTE: Replacement of the refrigerant line O-ring seals and gaskets is required anytime a refrigerant line or expansion valve is disconnected. Failure to
replace the rubber O-ring seals and metal gaskets may result in a refrigerant system leak.
The A/C expansion valve is factory calibrated and cannot be adjusted or repaired and must be replaced if inoperative or damaged.
