Refrigerant: Testing and Inspection

ON-VEHICLE INSPECTION

Problem Symptom Table:

1. INSPECT REFRIGERANT VOLUME
a. Check the sight glass on the liquid tube subassembly A.

Test conditions:
- Engine is running at 1,500 rpm.
- Blower speed control switch is at HI.
- A/C switch is ON.
- Temperature control switch is at the MAX. COOL position.
- Doors are fully open.

2. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
a. This method uses a manifold gauge set to locate problem areas. Read the manifold gauge pressure when these conditions are established.

Test conditions:
- Temperature at the air inlet is 30 to 35°C (86 to 95°F).
- Engine is running at 1,500 rpm.
- All doors are fully open.
- Blower speed control switch is at HI.
- Temperature control switch is at MAX. COOL.
- A/C switch is ON.




Gauge readings (Reference)







1 Normally functioning refrigeration system Gauge reading




2 The A/C system periodically changes between normal and improper function due to moisture in the refrigerant system.




3 The A/C system does not function effectively due to insufficient cooling.




4 The A/C system does not function effectively due to poor circulation of the refrigerant.

Part 1:

Part 2:

5 The A/C system does not function intermittently because the refrigerant does not circulate.




6 The A/C system does not function effectively due to overcharged refrigerant or insufficient cooling of the condenser.




7 The A/C system does not function due to air in the refrigeration system.

CAUTION: The low-pressure piping may be very hot and cause serious burns.




8 The A/C system does not function effectively due to an expansion valve malfunction.




9 The A/C system does not function due to a defective compressor.