Sequence of flushing procedure (sequence occurs automatically according to the A/C service station program)

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After turning on, the flushing circuit (refrigerant circuit with connecting hoses and flushing equipment for refrigerant circuits) is evacuated first and the refrigerant circuit is checked for leaks during this. Depending on the A/C service station version, it is possible that manually switching to advance the program is required. Refer to the operating instructions for the A/C service station.
A prescribed quantity of refrigerant (such as 5 kg) is filled into the evacuated refrigerant circuit via the high pressure side of the A/C service station (in opposite direction of normal flow when A/C system is in operation and also on the low pressure side of the vehicle refrigerant circuit), or, as much refrigerant is filled until refrigerant circuit and viewing glasses of refrigerant circuit flushing device are completely filled with fluid refrigerant (depending on version of A/C service station, recognized, for example, that refrigerant no longer flows from behind over a certain time period).
After the prescribed quantity of refrigerant has been filled, for example, the heater for the refrigerant circuit flushing device is turned on (only in the event the refrigerant is extracted in gaseous form from the refrigerant circuit flushing device), depending on version of A/C service station and refrigerant circuit flushing device.
After the refrigerant was extracted, the heating of the flushing device for refrigerant circuits is switched off (if present), it may occur that the refrigerant circuit is shortly evacuated again, depending on its version. After evacuation, the refrigerant extracted from the refrigerant circuit is deposited by the service station.
The sequence of filling refrigerant, extracting (and evacuating) is repeated twice (performed a total of three times). Refer to the operating instructions for the A/C service station.
After the third extraction, the flushing circuit is evacuated depending on the version of the A/C service station.

-- After the flushing procedure has ended, check the viewing glass(es) of refrigerant circuit flushing device, if they are soiled, clean them if necessary according to operating instructions of the refrigerant circuit flushing device or of the A/C service station and perform the flushing procedure once more as a test (one cycle is sufficient, duration approximately 30 minutes). refer to the operating instructions for the A/C service station.

-- Check the pressure in the refrigerant circuit, there must be no positive pressure in the refrigerant circuit (evacuate briefly once more if necessary).

-- Disconnect the connections to the A/C service station from the vehicle refrigerant circuit (there must be no positive pressure in the refrigerant circuit).

-- Replace these components depending on equipment (restrictor and reservoir, expansion valve and receiver/dryer or dryer cartridge in the receiver/dryer). Refer to [For engine(s) CTUA, CEUC, CRDB, CGXB, CPNB] System Overview - Refrigerant Circuit (vehicle-specific repair information) .

-- Replace the A/C compressor, depending on its condition. Refer to A/C Compressor Regulator ValveN280, Removing and Installing (vehicle-specific repair information) or drain the rest of the refrigerant oil still inside the removed A/C compressor (Refer to REFRIGERANT CIRCUIT COMPONENTS, REPLACING .) (replace the refrigerant circuit components) and will new refrigerant. Refer to APPROVED REFRIGERANT OILS AND CAPACITIES . (Approved Refrigerant Oils and Capacities).

NOTE:

There is a defined and prescribed amount of refrigerant oil in the replacement compressor. If the vehicle has two evaporators, then there refrigerant circuit requires a specific quantity of refrigerant oil. Refer to [For engine(s) CTUA, CEUC, CRDB, CGXB, CPNB] System Overview - Refrigerant Circuit (vehicle-specific repair information) and APPROVED REFRIGERANT OILS AND CAPACITIES . (Approved Refrigerant Oils and Capacities).

If the A/C compressor is not be replaced, the quantity of refrigerant oil in the A/C compressor must be topped off to the prescribed capacity (tilt the refrigerant oil out and refill the prescribed quantity into the A/C compressor or refrigerant circuit). Refer to REFRIGERANT CIRCUIT COMPONENTS, REPLACING (replacing refrigerant circuit components) and APPROVED REFRIGERANT OILS AND CAPACITIES . Approved Refrigerant Oils and Capacities).

-- Reassemble the refrigerant circuit completely. Refer to [For engine(s) CTUA, CEUC, CRDB, CGXB, CPNB] System Overview - Refrigerant Circuit (vehicle-specific repair information).

-- Evacuate and recharge the refrigerant circuit according to specification. Refer to REFRIGERANT CIRCUIT, DISCHARGING WITH SERVICE STATION and REFRIGERANT CIRCUIT, CHARGING WITH SERVICE STATION .

-- Start up A/C system according to specification. Refer to Refrigerant Circuit Components, Replacing (vehicle-specific repair information) and A/C SYSTEM, OPERATING AFTER CHARGING .