Pour in coolant and bleed cooling system - AR20.00-P-1142-04A

ENGINE 111, 112, 113, 137, 152, 156, 157, 166, 270, 271, 274, 275 

ENGINE 273 in MODEL 164, 207, 211, 212, 216, 219, 221, 230, 251 

Fig 1: Identifying Vacuum-Type Cooling System Filler (285 589 00 21 00)

Courtesy of MERCEDES-BENZ USA

Special tool The vacuum-type cooling system filler is needed.

Only vent cooling system for a cold engine.

1. Unscrew cooling system closure cap (10) and screw on test cap (2) at coolant expansion reservoir (1).
2. Attach control unit (3) to test cap (2).
3. Attach venturi nozzle (9) to control unit (3).
4. Close drain valve (8) and feed valve (7).
   Fig 2: Bleeding Cooling System

   Courtesy of MERCEDES-BENZ USA
5. Attach feed hose (4) of coolant to coolant container (4a)

   To avoid suctioning in of air put at least 2 l more coolant in the coolant reservoir (4a) than the maximum filling capacity of the cooling system.

6. Guide waste air hose (5) into an empty container (5a).
7. Connect compressed-air hose (6) to venturi nozzle (9) and apply pressure.

   The overpressure in the compressed air supply must be at least about 8 bar so that sufficient vacuum can be generated through the Venturi nozzle (9).

8. Open drain valve (8).

   A vacuum is created in cooling system.

9. Open feed valve (7) until feed hose (4) has filled with coolant.
10. Close drain valve (8) if display of the control unit (3) is in the green area.
11. Detach compressed air hose (6) from the venturi nozzle (9) and monitor whether vacuum remains stable for 30 seconds.

    If this is not the case, check hoses and connections and if necessary, repair and create a new vacuum.

12. Open feed valve (7).

    The cooling system is filled.

13. Open drain valve (8) if coolant is no longer suctioned.
14. Remove control unit (3) along with all connections and test cap (2).
15. Fill coolant up to bottom edge of filler neck of coolant expansion reservoir (1).
16. Screw cooling system closure cap (10) onto coolant expansion reservoir (1).