Radiator Pressure Flushing and Coolant Changing

m2+ m 20.03.000

Note:  For additional instructions on cleaning and flushing the cooling system, see the engine maintenance and operation manual.

Warning: Drain the coolant only when the coolant and engine are cool. Draining it when these are hot could cause severe personal injury due to scalding.

  1. Drain the radiator, as follows.
    1. Place a large container under the radiator.
    2. Remove the surge tank cap.
    3. Open the petcock at the bottom of the radiator to drain the engine coolant.
  2. Disconnect the radiator inlet and outlet hose connections.
  3. Flush the radiator, as follows.
    1. Attach a flushing gun nozzle to the radiator outlet.
    2. Add water to the radiator until it is full.

      3. Notice: When flushing the radiator, do not apply more than 20 psi (138 kPa) air pressure. Excessive pressure can damage the radiator or heater core.

    3. Apply no more than 20 psi (138 kPa) air pressure intermittently to help dislodge sediment buildup in the core.
  4. Drain the radiator, then flush the radiator until clean water flows from it. Remove the flushing gun.
  5. Close the petcock.
  6. Using clamps, connect the hoses to the radiator. Torque the clamps 33 to 38 lbf·in(370 to 430 N·cm).

    7. Important:  The coolant capacity varies depending on the engine and accessory installation. After servicing the cooling system, always verify that the coolant level is between the MIN and MAX lines on the surge tank.

  7. Fill the radiator with coolant. Refer to the engine manufacturer's service literature for specific coolant information.
Note:
Parent topic: Engine Cooling/Radiator
Document Number: 0000120386
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-11-06