Purpose
The expansion valve atomizes liquid refrigerant to facilitate cooling of the evaporator.
Function
The expansion valve reduces the pressure of liquid refrigerant rapidly to facilitate vaporization of the atomized refrigerant at the evaporator, and adjusts the refrigerant amount sent into the evaporator.
Construction
The expansion valve consists of the following parts:
Diaphragm
Temperature sensor
Shaft
Expansion valve body
Ball valve
Spring

Operation
Adjustment of the refrigerant amount supplied to the evaporator is performed by the ball valve opening angle in the expansion valve.
The opening angle adjustment is performed according to the balance of the following forces:

Refrigerant pressure (Pd) in diaphragm
Refrigerant gas pressure (PI) of evaporator under diaphragm
Spring force (Fs) pushing up ball valve
If the refrigerant gas temperature from the evaporator increases, the expansion valve increases the amount of refrigerant according to the following operations:

The temperature of the temperature sensor tightly sealed against the diaphragm increases.
The refrigerant in the diaphragm warms and the Pd increases.
If this Pd increases more than PI + Fs, the diaphragm is pressed down.
The shaft installed to the temperature sensor end presses down the ball valve.
The amount of refrigerant is increased.
If the refrigerant gas temperature from the evaporator decreases, the expansion valve decreases the amount of refrigerant flow according to the following operation:

The temperature of the temperature sensor tightly sealed against the diaphragm decreases.
The refrigerant temperature in the diaphragm decreases and the Pd decreases.
The Pd decreases less than PI + Fs.
The ball valve installed to the temperature sensor end is pressed up.
The amount of refrigerant is decreased.
Fail-safe
Function not equipped.
Evaporator Inspection
Expansion Valve Removal/InstallationFront Seat
Purpose, Function
The front seats are structured to reduce impact force applied to the head
of the occupant in a vehicle collision.
8WAY or 6WAY power seats have been adopted on the driver's seat. (with power
seat system).
A seat warmer system has been adopted on the ...
Fuel Pressure Sensor
Purpose/Function
Detects the fuel pressure in the fuel distributor as basic information for
mainly determining the fuel injection amount.
Detects the fuel pressure in the fuel distributor and inputs it to the PCM
as a fuel pressure signal.
Construction
Installed on ...
Propeller Shaft Removal/Installation
CAUTION:
If the constant velocity joint is bent during propeller shaft removal/installation
or transportation after servicing, the constant velocity joint boot may contact
the metallic cover and the boot may be damaged. Insert a rag between the boot
and the metallic cover before ser ...