Refrigerant: Testing and Inspection

HEATING / AIR CONDITIONING: REFRIGERANT: ON-VEHICLE INSPECTION

1. 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 1500 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)





Text in Illustration





(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.









(5) The A/C system does not function or 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.

NOTICE:
These gauge indications occur when the refrigeration system opens and the refrigerant is charged without vacuum purging.









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









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