Refrigerant Circuit, Discharging

Special tools and workshop equipment required 

• A/C Service Station

• Depending on the A/C Service Station used, changes to the work procedure may be needed. Pay attention to the Owner's Manual. Refer to Owner's Manual.

Procedure 

Vehicles with High-Voltage System

-- Deactivate the "parking air conditioner". Refer to Owner's Manual.

Vehicles with high-voltage system, for which electric activated valves in the refrigerant circuit are not open when de-energized.

-- Open the electric activated valves for the refrigerant circuit for extracting, evacuating and filling. Refer to Refrigerant Circuit and the .

Tip

For vehicles with high-voltage system and secondary functions of the A/C system, valves may be installed in the refrigerant circuit. To guarantee correct draining, evacuating and filling of the refrigerant circuit, no segments are allowed to be closed off. That is why the valves need to be opened before respective work procedures. Refer to Refrigerant Circuit .

Continuation for all vehicles

-- Switch off the ignition.

-- A/C Service Station on Refrigerant Circuit, Connecting. Refer to A/C SERVICE STATION ON REFRIGERANT CIRCUIT, CONNECTING .

-- Perform a gas analysis. Refer to REFRIGERANT GAS ANALYSIS, PERFORMING .

-- To empty the refrigerant circuit, select the high and low pressure connections at the A/C Service Station.

-- Discharge the refrigerant circuit using the A/C Service Station.

• Depending on the version of the A/C Service Station, it can generate a vacuum in the refrigerant circuit when extracting the refrigerant (residual pressure less than approximately 300 mbar).

-- Document the capacity of refrigerant oil which was also removed when evacuating the refrigerant. Refer to REFRIGERANT CIRCUIT, CHARGING .

Tip

Depending on the A/C Service Station, the automatic mode (program to evacuate and immediate filling of refrigerant) will automatically add the capacity of removed refrigerant oil when filling. Refer to Owner's Manual.

Should work be performed on the vehicle after discharging which does not require using the A/C Service Station:

-- Disconnect the A/C Service Station from the refrigerant circuit and turn it off. Refer to A/C SERVICE STATION, DISCONNECTING FROM THE REFRIGERANT CIRCUIT .

-- Perform procedures at the refrigerant circuit. Refer to Refrigerant Circuit .

Should the refrigerant circuit be evacuated and recharged after the discharging.

-- Refrigerant Circuit, Evacuating. Refer to REFRIGERANT CIRCUIT, EVACUATING .

• For vehicles with a mechanically driven A/C compressor and an empty refrigerant circuit, the engine can only be started if the refrigerant circuit is completely assembled. High speeds must be avoided.
• On vehicles fitted with a compressor with A/C Compressor Regulator Valve -N280- the engine should not be run for longer than absolutely necessary with the refrigerant circuit empty (A/C compressor always in operation as well).