Change Engine Coolant and Flush Cooling System

causym CAUTION: Explosive release of fluids from pressurized cooling system can cause serious burns.

Liquid cooling systems build pressure as the engine heats. Before removing the radiator cap, stop the engine and let the engine cool.

Remove the radiator cap ONLY after the system has cooled enough to touch with bare hands.

To avoid possible injury, turn the tank filler cap approximately 1/4 turn to relieve residual pressure before removing the cap completely.

1. Loosen the wingnut securing the cover and open the cover.

2. Remove the radiator cap.


A-Radiator Cap

TS281
T150236

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3. Open the radiator drain valve and drain the coolant into an appropriate container.

Specification

Cooling System -Capacity 30 L (8 gal)

NOTE: Dispose of waste properly.


B-Radiator Drain Valve

T148131

Radiator Drain Valve

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4. Open the engine coolant drain valve and drain coolant into an appropriate container.

IMPORTANT: When all coolant has drained, close the coolant drain valves on the radiator and engine.

IMPORTANT: When filling the cooling system, air must be vented from the engine coolant passages. The system must be filled slowly to prevent air locks.

6. Fill the cooling system with the specified mixture of fresh water and sodium carbonate.

Specification

Cooling System Flushing Solution -Ratio 1/2 kg (1 lb.) of sodium carbonate to 20 L (6 gal) of water

IMPORTANT: DO NOT install the radiator cap at this time. The engine should be operated without pressure in the cooling system.

7. Operate the engine approximately five minutes with the coolant temperature above the specified temperature.

Specification

Cooling System Flush Operating Temperature -Temperature Above 80° C (176° F)

8. Shut the engine down and drain the cooling system using the radiator drain valve and the engine drain plug.

9. Drain and refill radiator several times using clean water (only) to flush the system.

10. When all water has drained, close the radiator drain valve and install the engine drain plug.

11. Fill the cooling system with coolant. See Section 3-1 for recommended engine coolant.

To fill the cooling system:

a. Fill the radiator completely.

b. Fill the expansion tank to the proper level.

T150402


C-Engine Coolant Drain Valve

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c. Top off the radiator a second time.

d. Start the engine. Run the engine under load for 20 minutes. Coolant should reach normal operating temperature of 93°C (200°F).

e. Shut off the engine and allow the system to cool completely.

f. Add coolant to the expansion tank as required.

NOTE: The coolant level should drop after running the engine. If the coolant level does not drop, there may be a problem with the cooling system. Diagnose the problem and repeat the filling procedure.

12. Install the radiator cap. Tighten the wingnut to secure the cover.

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