Electrically-Driven A/C Compressor, Flushing (Removing Refrigerant Oil)

Vehicles With A High-Voltage System (Hybrid Vehicles)

-- Individuals With Electronic/Medical Life And Health Sustaining Machines In Or On Their Person Cannot Perform Any Work On High-Voltage Systems. Some Examples Of Life And Health Sustaining Machines Are Pain Killer Pumps, Implanted Defibrillators, Pacemakers, Insulin Pumps, And Hearing Aids.

-- Have The High-Voltage System De-Energized By A Qualified Person.

-- Switch Off The Ignition.

-- Place The Ignition Key Outside Of The Vehicle Interior.

-- Never Support Objects On The High-Voltage Cables And The High-Voltage Connectors.

-- Never Support Tools On The High-Voltage Cables And The High-Voltage Connectors.

-- Never Sharply Bend Or Kink The High-Voltage Cables.

-- When Connecting Pay Attention To The Coding Of The High-Voltage Connectors.

• For all procedures on vehicles with a high-voltage system, pay attention to the additional warnings for these vehicles. Refer to WARNINGS WHEN WORKING ON VEHICLES WITH HIGH VOLTAGE SYSTEM .
• If procedures are necessary near components of the high-voltage system, "visually inspect the high-voltage components and lines for damage". Refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES .
• If work on the high-voltage system components is necessary, de-energize the high-voltage system. Refer to The Appropriate Service Information. .

-- Charge the vehicle batteries, for example, using the Battery Charger:VAS5904  in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active. Refer to BATTERY, CHARGING and WARNINGS WHEN WORKING ON VEHICLES WITH HIGH VOLTAGE SYSTEM .

-- For testing and measurement procedures that require the ready mode to be active or the ignition to be switched on, the selector lever must be in the "P" position and the parking brake must be activated. The required tools must be placed so that they do not come into contact with any rotating components in the engine and they must also not go into the vicinity of the rotating components when the engine is running.

General Notes To Remove The Refrigerant Oil From The Electrically Driven A/C Compressor (By Flushing).

• The electrically driven A/C compressor is to be flushed when, there is dirt, too much refrigerant oil is in the refrigerant circuit, or is contaminated (with moisture debris) and to remove refrigerant oil from the A/C compressor. In these cases the refrigerant circuit must also be flushed, so that it will be cleaned and the correct refrigerant oil quantity for the refrigerant circuit can be set. Refer to REFRIGERANT OIL CAPACITIES .
• If the electrically driven A/C compressor is replaced, it is not always necessary to flush the coolant circuit. The amount of refrigerant oil found in the removed A/C compressor can be removed by flushing the A/C compressor. Pour the refrigerant oil out of the new A/C compressor so that only the amount remains (plus 10 cm ³ ) as before the old A/C compressor was flushed out. Refer to COMPRESSOR, REPLACING WITHOUT THE NEED FOR FLUSHING REFRIGERANT CIRCUIT .
• To remove the refrigerant oil from the removed A/C compressor the refrigerant oil must be flushed from the replaced A/C compressors and the removed amount measured (Empty the used oil collection from the A/C service station before flushing). Pour the refrigerant oil out of the new A/C compressor so that only the amount or refrigerant oil remains (plus 10 cm ³ ) in the new A/C compressor as the amount of flushed out refrigerant oil from the old A/C compressor. Dispose of the refrigerant oil removed from the defective and the new A/C compressor and poured out refrigerant oil from the new A/C compressor. Refer to Audi Service Net, HSO Environment (pay attention to local regulations).
• If not enough refrigerant oil can be poured out from the A/C compressor to be installed, flush the new A/C compressor. Fill the A/C compressor to be installed in after flushing with as much new refrigerant oil as was flushed from the removed A/C compressor. Example: 120 cm ³ of refrigerant oil was flushed out of the removed A/C compressor and there is 200 cm³ in the new A/C compressor to be installed (refer to the type plate and REFRIGERANT OIL CAPACITIES ). 110 cm³ (120 cm³ minus 10 cm³ ) must be poured out of the A/C compressor to be installed so that the amount of refrigerant oil in the refrigerant circuit after installing is correct. If the required amount of refrigerant oil cannot be poured out, flush the A/C compressor to be installed. In the new A/C compressor as much refrigerant oil is to be filled as was flushed out of the old A/C compressor.

Flush the electrically driven A/C compressor.

Courtesy of AUDI OF AMERICA, LLC

1. A/C Service Station
   • With electronics and a flushing program, A/C Service Station With Flushing Device. Refer to parts information (Tools; Special Tools and Equipment: A/C and Heating).
   • If an A/C service station without a flushing program is used, the procedure must be performed manually (evacuate, flush three times with at least 2 kg refrigerant each and extract refrigerant again, evacuate).
2. A/C Service Station Refrigerant Hose
   • From the high pressure side of the A/C service station (mostly colored red) to the connection for the low pressure side of the A/C compressor on the refrigerant circuit (larger diameter).
3. Adapter to the Connection for the Low Pressure Side on the A/C Compressor
   • There are different versions depending on the vehicle. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
   • Use the adapter from the Refrigerant Circuits Adapter Set 1:VAS6338/1  (here the Adapter:VAS6338/41  ).
4. Refrigerant Line
   • For connecting the A/C compressor to the adapter -item  ) ELECTRICALLY-DRIVEN A/C COMPRESSOR, FLUSHING (REMOVING REFRIGERANT OIL).
     NOTE:

     Only use the refrigerant line when the Adapter:VAS6338/41  is not available.

     If the Adapter:VAS6338/41  is not available to remove the flushing circuit, for example remove the refrigerant lines to the condenser, from the vehicle (or use a refrigerant line with the part number 7L6 820 744 AD). Refer to the parts information).

5. Electrically-Driven A/C Compressor
   • The A/C compressor is flushed in the flow direction (from the low pressure side input to the high pressure side output)
   • So that as much refrigerant oil as possible is flushed out from the A/C compressor, the A/C compressor must be positioned so that the high pressure side output is as low as possible
     CAUTION:

     Risk To A/C Service Station Function Depending On The Version And The Amount Of Refrigerant Oil In The A/C Compressor

     • Depending on the A/C service station version, the oil amount that is deposited in one step may be limited (100 cm³ , for example). Pay attention to the A/C service station operating instructions and technical product description.
     • Depending on the A/C compressor, a larger amount of refrigerant oil (for example, 290 cm³ on an Audi Q7 e-tron) may be filled in a new A/C compressor (refer to REFRIGERANT OIL CAPACITIES and COMPRESSOR, REPLACING WITHOUT THE NEED FOR FLUSHING REFRIGERANT CIRCUIT ).
     • On a new A/C compressor that is filled with more than 150 cm³ , pour out as much refrigerant oil as possible (via the high and low pressure connection) into a clean container before flushing. This prevents the A/C service station oil separator from overfilling during the flushing procedure.
     • Then flush the rest of the refrigerant oil out of the A/C compressor.
     NOTE:

     If the clean refrigerant oil is poured out of a new A/C compressor into a clean container and the A/C compressor is then sealed air-tight, this refrigerant oil can be reused to adjust the amount of refrigerant oil in the circuit.

6. Refrigerant Line
   • For connecting the A/C compressor to the adapter -item  ) ELECTRICALLY-DRIVEN A/C COMPRESSOR, FLUSHING (REMOVING REFRIGERANT OIL).
     NOTE:

     Only use the refrigerant line when the Adapter:VAS6338/40  is not available.

     If the Adapter:VAS6338/40  is not available to remove the flushing circuit, use for example, a refrigerant line with the part number 7L6 820 721 BF or 4G0 260 701 AB. Refer to parts information.

7. Adapter to the High Pressure Side Connection on the Refrigerant Circuit
   • There are different versions depending on the vehicle. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .
   • Use the adapter from the Refrigerant Circuits Adapter Set 1:VAS6338/1  (here the Adapter:VAS6338/40  ).
8. Charging Hose for Refrigerant Circuit Flushing Device
   • From the connection to the high pressure side of the A/C compressor on the refrigerant circuit (smaller diameter) to the input of the refrigerant circuit flushing device.
9. Refrigerant Circuit Flushing Device
   • There are different versions of the Refrigerant Circuit Flushing Device. Refer to the parts information (Tools; Special Tools and Equipment: A/C and Heating).
   • With filter, viewing glass, safety valve, heater, refrigerant reservoir, etc. (Depending On Version).
   • Depending on the construction of the A/C service station and of refrigerant circuit flushing device, a check-valve may be installed at output of refrigerant circuit flushing device (to guarantee correct direction of refrigerant flow during flushing).
   • Depending on the design of the refrigerant circuit flushing device, a connection for a refrigerant circuit service coupling may be located at the outlet (and possibly also at the inlet) of the flushing device (instead of a 5/8-18 UNF external thread). If a service connection with a valve is installed on the outlet of the flushing device, this valve must be all the way open when the service coupling is attached (a partially opened valve creates a constriction). If there is a connection for a service coupling on the inlet of the flushing device, the inlet must be modified so that the refrigerant hose coming from the vehicle can be directly connected (a service coupling and a valve in the flushing device inlet create a constriction that impedes the flow of refrigerant from the vehicle to the flushing device and thus the flushing procedure).
     CAUTION:

     Risk Of Icing Over The Output Of The Flushing Device Via The Installed Valve Which Is Not Correctly Opened.

     • A partially opened valve installed in this connection creates a constriction that impairs the flow of refrigerant in the flushing device and can ice over due to severe cooling.
     • If there is a service connection with a valve on the outlet of the flushing device, this valve must be all the way open during the flushing procedure.
     • If there is too strong of cooling (icing over) at the outlet of the flushing device during the flushing procedure, stop the flushing procedure and evacuate the refrigerant from the flushing device and the vehicle via the high and low pressure side. Check the valve in the outlet of the flushing device and service it if necessary.

     Risk of icing on the input of the flushing device due to a constriction which is created via a service coupling and in a service connection installed valve.

     • Remove the service connection installed on this connection, and connect the service hose that comes from the vehicle directly (without constriction) to the flushing device, possibly using a necessary adapter (depending on the inlet thread of the flushing device).
10. A/C Service Station Refrigerant Hose
    • From the A/C service station low pressure side (mostly blue) to the outlet of the refrigerant circuit flushing device.