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/InstallationRear Upper Arm Removal/Installation [Awd]
WARNING:
Verify that the crossmember is securely supported by a jack. If the rear
crossmember falls off, it can cause serious injury or death, and damage to the
vehicle.
CAUTION:
Performing the following procedures without first removing the rear ABS wheel-speed
...
Child Restraint Precautions
Mazda strongly urges the use of child-restraint systems for children small enough
to use them.
You are required by law to use a child-restraint system for children in the U.S.
and Canada.
Check your local and state or provincial laws for specific requirements regarding
the safety of children ...
Wheel Hub, Steering Knuckle Inspection
Wheel Bearing Excessive Play Inspection
1. Install the magnetic base and dial gauge as shown in the figure and measure
the wheel bearing axial excessive play.
If it exceeds the maximum specification, replace the wheel hub bearing.
Front wheel bearing maximum play
0 ...