Refrigerant: Testing and Inspection

REFRIGERANT

ON-VEHICLE INSPECTION

1. INSPECT REFRIGERANT VOLUME




a. Check the sight glass on the liquid tube.




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







1. If the refrigeration system is functioning normally, the gauge readings are as shown in the table.







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