Refrigerant - Charge
REFRIGERANT SYSTEM CHARGEWARNING: REVIEW THE WARNINGS AND CAUTIONS BEFORE PERFORMING THE FOLLOWING OPERATION.
After the refrigerant system has been tested for leaks and evacuated, a refrigerant charge can be injected into the system. Refer to Refrigerant Charge Capacity for the proper amount of the refrigerant charge.
A R-134a refrigerant recovery/recycling/charging station that meets SAE Standard J2210 must be used to charge the refrigerant system with R-134a refrigerant. See the operating instructions supplied by the equipment manufacturer for proper care and use of this equipment.
Refrigerant Charge Capacity
The R-134a refrigerant system charge capacity for this vehicle is 0.709 kilograms (1.56 pounds/25 ounces).
Partial Charge Method
WARNING: REVIEW THE WARNINGS AND CAUTIONS BEFORE PERFORMING THE FOLLOWING OPERATION.
The partial charge method is used to add a partial charge to a refrigerant system that is low on refrigerant. To perform this procedure the evaporator inlet and outlet tube temperatures are measured. The temperature difference is measured with a temperature meter with one or two clamp-on thermocouple probes. The difference between the evaporator inlet and outlet tube temperatures will determine the amount of refrigerant needed.
Before adding a partial refrigerant charge, check for refrigerant system leaks. Refer to Refrigerant System Leaks for the proper procedures. If a leak is found, make the necessary repairs before attempting a full or partial refrigerant charge.
1. Attach a manifold gauge set to the refrigerant system service ports.
2. Attach the two clamp-on thermocouple probes to the inlet and outlet tubes of the evaporator coil.
a. If a single thermocouple probe is used, attach the probe to the liquid line just before the connector block for the evaporator. The probe must make contact with the bottom surface of the liquid line.
b. If dual thermocouple probes are used, attach probe 1 to the liquid line, and probe 2 to the suction me. Attach both probes to the lines just before the connector block for the evaporator. The probes must make contact with the bottom surfaces of the liquid line and the suction line.
3. Open all of the windows or doors of the passenger compartment.
4. Set the heater-A/C controls as follows: Airflow control in Recirculation, Mode control in Panel, Temperature control to the full Cool position, Blower control in the highest speed position in the A/C compressor ON direction.
5. Start the engine and hold the engine idle speed at 1,000 rpm. Allow the engine to warm up to normal operating temperature.
6. The compressor clutch may cycle, depending upon ambient temperature, humidity, and the refrigerant system charge level. If the compressor clutch cycles, unplug the wire harness connector from the low pressure clutch cycling switch on the accumulator. Install a jumper wire between the two cavities of the switch wire harness connector.
7. Hold the engine idle speed at 1,000 rpm.
8. Allow three to five minutes for the refrigerant system to stabilize, then record the temperatures of the liquid line and the suction line.
a. If a single probe is used, record the temperature of the liquid line. Then remove the probe from the liquid line and attach it to the suction line just before the connector block for the evaporator. The probe must make contact with the bottom surface of the suction line. Allow the thermocouple and meter time to stabilize, then record the temperature of the suction line. Subtract the liquid line temperature reading from the suction line temperature reading.
b. If dual probes are used, record the temperatures of both the liquid line and the suction line. Then subtract the liquid line temperature reading from the suction line temperature reading.
9. If the measured temperature differential is higher than 22 °C to 26 °C (40 °F to 47 °F), add 0.4 kilograms (14 ounces) of refrigerant.
10. Allow three to five minutes for the refrigerant system to stabilize, then take a second set of thermocouple measurements. Record the temperature difference to determine if an additional charge is required.
Fig.31 Compressor Discharge Pressure:
11. Record the compressor discharge pressure. If the reading is higher than the pressure shown in the Compressor Discharge Pressure chart, the system could be overcharged. If the reading is equal to, or lower, than the pressure shown in the chart, continue with this procedure.
12. EXAMPLE: The ambient temperature is 21 °C (70 °F). The evaporator inlet tube temperature is 12 °C (54 °F) and the evaporator outlet tube temperature is 10 °C (50 °F). Subtract the inlet tube temperature from the outlet tube temperature. The difference is 2 °C (-4 °F). With a -2 °C (-4 °F) temperature differential at 21 °C (70 °F) ambient temperature, the system is fully charged.
13. Add enough refrigerant to bring the refrigerant system up to a full charge.
14. Remove the jumper wire from the low pressure clutch cycling switch wire harness connector and reconnect the connector to the switch.