System Charging

Charging from Small Containers

The refrigerant charge level of A/C systems currently being used is critical to optimum performance. Either an under-charge or an over-charge will adversely affect performance. Using small cans to charge these systems is not recommended because the charge level cannot be accurately controlled. A charging cylinder or a charging station is the only recommended method.

Charging with a Charging Cylinder

1. If the vehicle suction (low) side service port is located on the suction accumulator/drier (19C836) , connect the gauge set center hose to the liquid port of the charging cylinder. If the suction (low) side service port is NOT on the suction accumulator/drier (located on the suction hose), connect the center hose to the gas port of the charging cylinder.

    WARNING: LIQUID CHARGE INTO THE VEHICLE SUCTION ACCUMULATOR/DRIER ONLY. TO PREVENT A/C COMPRESSOR (19703) SLUGGING, DO NOT LIQUID CHARGE INTO A REFRIGERANT HOSE WHILE THE ENGINE IS OPERATING.

2. When evacuating the system with the vacuum pump, the gauge set second center hose should be connected to the charging cylinder and opened to the gauge set so that the hose will evacuate with the system.

3. When evacuation of the system is completed, close the center hose valve to the vacuum pump and turn the pump off.

4. Open the charging cylinder valve and the gauge set low side valve to allow refrigerant to enter the system.

5. When no more refrigerant is being drawn into the system, start the engine and select an A/C function on the control assembly. Then move the blower function setting to high to allow the remaining refrigerant to be drawn into the system. Continue to add refrigerant into the system until the specified weight of R-134a has been added. Then close the charging cylinder valve and allow the system to pull any remaining refrigerant from the hose. When the suction pressure drops to approximately 207 kPa (30 psi), close the gauge set center hose valve.

6. Operate the system until the pressures stabilize to verify normal operation and system pressures.

7. In high ambient temperatures, it may be necessary to operate a high-volume fan positioned to blow air through the A/C condenser core (19712) and radiator (8005) to aid in cooling the engine and prevent excessive refrigerant system pressures.

8. When charging is complete, close the valves at the ends of the low and high hoses if not equipped with automatic closing valves. Then disconnect the manifold gauge set hoses from the vehicle and install the A/C charging valve caps (19D702) on the service gauge port fittings.