1. Park the car on level ground and turn off the engine. Allow it to cool down completely.
2. Open the hood and locate the radiator cap. It is usually a black or blue plastic cap located at the top of the radiator.
3. Place a pan or bucket underneath the radiator drain plug. The drain plug is usually located at the bottom of the radiator on the driver's side.
4. Loosen the radiator drain plug and allow the coolant to drain out. Be careful not to spill any coolant on yourself or the paint of the car.
5. Once the coolant has drained completely, close the drain plug.
6. Refill the radiator with the appropriate coolant mixture (usually 50/50 mix of coolant and water). Subaru recommends using genuine Subaru coolant.
7. Start the engine and let it idle for a few minutes.
8. Turn on the heater to high and allow it to run for a few minutes. This will help circulate the coolant throughout the system.
9. Check the coolant level in the radiator and add more coolant if necessary.
10. Close the radiator cap and turn off the engine.
Now the cooling system in your 2003 Subaru Legacy should be bled.
