Refrigerant: Testing and Inspection

REFRIGERANT

ON-VEHICLE INSPECTION

1. CHECK REFRIGERANT PRESSURE USING MANIFOLD GAUGE SET
a. This is a method to identify trouble areas by using a manifold gauge set. Read the manifold gauge pressure under the given conditions.
Test conditions:
- Engine warm.
- All doors fully open.
- A/C switch ON.
- Blower speed control switch at HI.
- Engine running at 1,500 rpm.
- Air inlet mode damper set at recirculation.
- Temperature control lever in MAX. COLD position.
- Air temperature at air inlet 30 to 35°C (86 to 95°F).




1. When the refrigerant volume is correct, the gauge reading indicates as given:

Low pressure side: 0.15 to 0.25 MPa (1.5 to 2.5 kgf/sq.cm)
High pressure side: 1.37 to 1.57 MPa (14 to 16 kgf/sq.cm)

HINT: Pressure varies in accordance with certain conditions (outside air temperature, sunlight and wind).







2. When there is moisture in the refrigeration system







3. When cooling is insufficient







4. When the circulation of the refrigerant is poor







5. When the refrigerant does not circulate







6. When the refrigerant is overcharged or cooling of condenser is insufficient







7. When there is air in the refrigeration system







8. When the expansion valve malfunctions







9. When the compressor is defective:

2. INSPECT IDLING SPEED
a. Warm up the engine.

b. Inspect the idling speed when these conditions are established.
- Engine warm
- Blower speed control switch at HI
- Temperature control lever in MAX. COLD position




If the idling speed is not as specified, check the idle control system.