A/C PERFORMANCE TEST — Performance Test Diagnoses (page 1)
HA-35spec tablePerformance Test Diagnoses
Characteristics revealed by the manifold gauge readings for the air conditioning system are shown in the following.
NOTE
For how to do the performance test, refer to the item "Performance Chart".
In the following table, the portion smeared with ink on each gauge scale indicates the range showing that the air conditioning system is in good order. This range is described in Performance Chart.
Performance test diagnosis (page 1 of N) — Insufficient charge / no refrigerant / expansion valve
INSUFFICIENT REFRIGERANT CHARGE (AC352A)
SymptomInsufficient cooling. Bubbles appear in sight glass.
Probable causeRefrigerant is low, or leaking slightly.
Corrective action1. Leak test. 2. Repair leak. 3. Charge system. Evacuate, as necessary, and recharge system.
ALMOST NO REFRIGERANT (AC353A)
SymptomNo cooling action. A lot of bubbles or something like mist appears in sight glass.
Probable causeSerious refrigerant leak.
Corrective actionStop compressor immediately. 1. Leak test. 2. Discharge system. 3. Repair leak(s). 4. Replace receiver drier if necessary. 5. Check oil level. 6. Evacuate and recharge system.
MALFUNCTIONING EXPANSION VALVE (AC354A)
SymptomSlight cooling. Sweat or frosting on expansion valve inlet.
Probable causeExpansion valve restricts refrigerant flow. Expansion valve is clogged. Expansion valve is inoperative — valve stuck closed; thermal bulb has lost charge.
Corrective actionIf valve inlet reveals sweat or frost: 1. Discharge system. 2. Remove valve and clean it. Replace it if necessary. 3. Evacuate system. 4. Charge system. If valve does not operate: 1. Discharge system. 2. Replace valve. 3. Evacuate and charge system.