Grand Caravan V6-3.3L VIN E Flex Fuel (2007)
Expansion Valve: Description and Operation
A/C Expansion Valve - Front
Description
DESCRIPTION
The front A/C expansion valve (Figure 1) controls the amount of refrigerant entering the front A/C evaporator. The front A/C expansion valve is of a
thermostatic expansion valve (TXV) design and consists of an aluminum H-valve type body with an integral thermal sensor. The front A/C expansion
valve is located in the engine compartment at the dash panel, between the A/C refrigerant lines and the A/C evaporator.
On RG models, the evaporator temperature sensor is installed on the top of the front A/C expansion valve.
Figure 1 A/C Expansion Valve-Typical
Operation
OPERATION
The A/C expansion valve controls the high-pressure, low temperature liquid refrigerant from the liquid line and converts it into a low-pressure,
low-temperature mixture of liquid and gas before it enters the A/C evaporator. A mechanical sensor in the A/C expansion valve monitors the temperature
and pressure of the refrigerant leaving the A/C evaporator through the suction line, and adjusts the orifice size at the liquid line port to let the proper
amount of refrigerant into the A/C evaporator to meet the vehicle A/C cooling requirements. Controlling the refrigerant flow through the A/C evaporator
ensures that none of the refrigerant leaving the A/C evaporator is still in a liquid state, which could damage the A/C compressor.
The A/C expansion valve is a factory calibrated unit and cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
