Check Refrigerant Gas Pressure

Preparation tool: 

Manifold gauge set 

Thermometer and hygrometer 

1. Prepare the vehicle.
   NOTE: Check that the ambient temperature is 25 - 40°C (77 - 104°F) and that the humidity is 30% - 80%.
   • Place the vehicle in the shade and windless condition, and open the front hood.
   • Open all windows and close all doors.
2. Connect the manifold gauge set, and then check the refrigerant pressure.
   1. Connect the manifold gauge set, and start the engine.
   2. Set the vehicle to the following conditions.

      Item	Condition
      Engine	Warmed up (Engine coolant temperature indicator light: OFF)
      Air vent grille	Shutter is fully open.
      AC switch	ON
      Temperature control switch or dial	LO (MAX COOL)
      FRESH/RECIRC switch	RECIRC
      Air flow control switch	VENT
      Fan switch (auto A/C model)	4 - 6 levels
      Fan dial (manual A/C model)	3 - 4 levels

   3. In the condition of step ( 2), idle the engine for 30 minutes.
   4. Read the gauge values on both high pressure side and low pressure side for manifold gauge.
3. Measure the air vent grille outlet opening temperature, ambient temperature and humidity.
   NOTE: For outlet opening temperature, measure the average temperature of center grille assembly and side grille assembly.
4. Check that the high and low pressures and outlet opening temperature for ambient temperature and humidity is within the standard value described in the chart below.
   Fig 1: Air Flow Outlet Temperature Versus Ambient Temperature Graph

   Courtesy of SUBARU OF AMERICA, INC.
5. Refer to INSPECTION WITH PRESSURE SYMPTOM .