1. Park the vehicle on level ground and turn off the engine. Allow the engine to cool down completely.
2. Locate the coolant reservoir. In most Lumina models, it's a translucent plastic container with a black cap located near the front of the engine compartment.
3. Check the coolant level. The reservoir should have "FULL" and "ADD" marks. The coolant level should be between these two marks.
4. If the coolant level is low, add a mixture of 50% antifreeze and 50% distilled water. Use the appropriate antifreeze type recommended in the owner's manual.
5. Continue adding coolant until the level reaches the "FULL" mark.
6. Replace the coolant reservoir cap securely.
7. Start the engine and let it run for a few minutes.
8. Turn off the engine and allow it to cool down.
9. Recheck the coolant level in the reservoir. If necessary, add more coolant to bring it back to the "FULL" mark.
Always refer to your vehicle owner's manual for specific instructions related to your model.
