Which maintenance task is crucial for preventing engine overheating?

The maintenance task that is crucial for preventing engine overheating is the replacement of coolant. Coolant plays a vital role in regulating engine temperature by absorbing heat from the engine and dissipating it through the radiator. Over time, coolant can degrade due to contamination, oxidation, or the breakdown of its chemical additives. If the coolant is not replaced regularly, its effectiveness diminishes, which can lead to increased engine temperatures and ultimately engine overheating.

In contrast, while oil changes contribute to the overall health of the engine by ensuring proper lubrication and reducing friction, they do not directly address cooling issues. Brake fluid checks are important for brake performance but are unrelated to engine temperature control. Tire rotation improves tire wear and vehicle handling but does not affect engine operation or cooling. Thus, maintaining optimal coolant condition is key to preventing overheating and ensuring the engine operates within a safe temperature range.