Prepare the low temperature circuit for the bleeding process - AR20.00-P-1145-02R

1. Connect the connections (A, B) to the service connections of the charge air cooler.
   Fig 1: Identifying Charge Air Cooler Connection

   Courtesy of MERCEDES-BENZ USA
2. Close all the valves (C, D, H, HA, O, P) on the control unit, the Y-fitting and the vacuum box.
   Fig 2: Identifying Valves On Control Unit, Y-Fitting And Vacuum Box

   Courtesy of MERCEDES-BENZ USA

   All the connections described in steps 3 to 5 will be maintained throughout the bleeding process. Interchanging the hoses (E, J, S) will damage the bleeding devices.

3. Connect the coolant feed (J) to connection (N).
4. Connect the coolant drain (E) to connection (F).
5. Lay down the waste air hose (S) in the receptacle.
   Fig 3: Identifying Connections For Bleeding Process

   Courtesy of MERCEDES-BENZ USA
   Fig 4: Identifying Connections Of Control Unit And Venturi Nozzle

   Courtesy of MERCEDES-BENZ USA
6. Connect the control unit (5) to the test connection - connection (L) to the test connection.
7. Connect the venturi nozzle (6) to the control unit (5) - connection (U) to connection (T).
8. Connect the compressed air (Z) to the venturi nozzle (6) - compressed air (Z) to connection (M).

   An audible air discharge is normal.

9. Generate a vacuum in the control unit (5) - open valve (P).
10. By regulating the valve (O) (arrow), draw in the coolant up to the control unit (5) by suction. Then again close valve (O).
    Fig 5: Identifying Control Unit And Valve

    Courtesy of MERCEDES-BENZ USA
11. Test the low temperature circuit for leaks - close valve (P).

    The unchanged display (arrow) of the pressure gauge shows that the vacuum has been maintained, thereby indicating the leak tightness of the low temperature circuit.

    Fig 6: Testing Low Temperature Circuit Leaks - Close Valve

    Courtesy of MERCEDES-BENZ USA
    Fig 7: Identifying Venturi Nozzle And Control Unit

    Courtesy of MERCEDES-BENZ USA
12. Detach the venturi nozzle (6) from the control unit (5).

The display of the pressure gauge (arrow) must continue to show a vacuum even after the preparatory tasks have been completed.