Durango 2WD V8-4.7L (2008)
Expansion Valve: Description and Operation
Plumbing - Rear
Description
DESCRIPTION
The rear A/C expansion valve is of a thermostatic expansion valve (TXV) design and controls the amount of refrigerant entering the rear A/C evaporator.
The rear A/C expansion valve consists of an aluminum H-valve type body (1) with an integral thermal sensor (2) and is located on the rear HVAC
housing between the rear evaporator extension tubes and the rear evaporator.
Operation
OPERATION
The rear 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 rear A/C evaporator. To meet the vehicles A/C cooling requirements, a
mechanical sensor is used in the rear A/C expansion valve to monitor the temperature and pressure of the refrigerant leaving the rear 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
rear 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 rear A/C expansion valve is factory calibrated and cannot be adjusted or repaired and must be replaced if inoperative or damaged
