What should be done after flushing a cooling system before refilling?

After flushing a cooling system, it is essential to bleed air from the system before refilling it. When a cooling system is flushed, air can become trapped in the system, which can lead to overheating issues due to inadequate coolant circulation. Bleeding the air helps eliminate these pockets, ensuring that the cooling system operates effectively.

While ensuring that the fresh antifreeze matches the old color may seem relevant, it is more important to focus on the compatibility and specifications of the coolant rather than its color. Regarding using water for the refill, using pure water can lead to corrosion and lower boiling points in the long run. Therefore, it's critical to use the appropriate mixture of antifreeze and water as specified by the vehicle manufacturer.

Thus, the best course of action includes bleeding the system as a priority and making sure that the coolant mixture is appropriate for optimal performance. While other considerations may apply, the crucial step following a flush is to ensure that the system is free of air. Hence, all suggested actions are significant in the context of adequately preparing the cooling system for operation after a flush.