Refrigerant: Testing and Inspection
ON-VEHICLE INSPECTION1. 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.
b. Gauge readings (Reference)
1. Normally functioning refrigeration system
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.
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.
Gauge readings (Reference)