Coolant Flushing and Changing

Coolant Flushing and Changing - EuroV MBE900

Warning: HOT COOLANT

To avoid scalding from the expulsion of hot coolant, never remove the cooling system pressure cap while the engine is at operating temperature. Wear adequate protective clothing (face shield, rubber gloves, apron, and boots). Remove the cap slowly to relieve pressure.

Flush and change the coolant as follows:‪

  1. Open the cap on the surge tank slowly, to allow excess pressure to escape. Set the cap aside.
  2. Open the water regulating valve for the heating system.
  3. Drain the coolant from the engine. Coolant system capacity is listed in the "Coolant System Capacity" table below.
    1. Place a receptacle underneath the coolant drain plug. Choose one that is large enough to hold the expected quantity of coolant.

      Fig. 1, Coolant Drain Plug

    2. Open the coolant drain plug on the bottom of the radiator.
    4. Notice: When flushing the radiator, do not apply more than 140 kPa (20 psi) air pressure. Excessive pressure can damage the radiator or heater core.‪
  4. Flush the radiator, then attach a flushing gun nozzle to the radiator outlet.
    1. Run water in until the radiator is full.

      2. Warning: EYE INJURY

      To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.

    2. Apply no more than 140kPa (20 psi) air pressure intermittently to help dislodge sediment buildup in the core.
  5. Drain the radiator, and flush the radiator until clean water flows from the radiator. Remove the flushing gun.
  6. When the coolant has drained, install the coolant drain plug on the radiator.
  7. Add coolant in the specified concentration until the maximum mark on the surge tank is reached. Coolant system capacity is listed below.
    Coolant System Capacity
    Description‪ 4-Cylinder 6-Cylinder
    Engine Coolant Capacity (all vehicles) L (Qt)‪
    Engine capacity 8 (8.5)‪ 12 (12.7)‪
    Business Class Coolant System Capacity L (Qt)‪
    Total capacity 19.8 (21)‪ 23.6 (25)
    Antifreeze quantity at 50%‪ 9.9 (10.5) 11.8 (12.5)
    Antifreeze quantity at 55% 10.8 (11.5) 13.1 (13.8)
    1. Start the engine and run it for about one minute at varying speeds to release air pockets in the cooling system. Make sure the heater valve is still open. Check the coolant level and add more coolant if necessary.
    2. Shut down the engine.
    3. Add coolant if necessary.
    Note:
    Parent topic: Maintenance
    Document Number: 0000035944
    Manual Publication Date: 2024-01-05
    Topic Publication Date: 2023-03-28