What should be checked in the sight glass of the radiator surge tank?

When checking the sight glass of the radiator surge tank, it is crucial to confirm that the fluid level is within the proper range. The sight glass provides a clear view of the coolant level, allowing the driver or technician to easily determine if there is sufficient fluid. An appropriate fluid level is necessary to ensure adequate cooling of the engine. If the coolant level is too low, it can lead to overheating and potentially severe engine damage. Maintaining the proper range not only supports optimal engine performance but also contributes to the longevity of the cooling system.

While other aspects might be important during a pre-trip inspection—such as checking for leaks, ensuring secure mounting of the tank, and verifying that connections are intact—these elements are secondary when it comes to assessing the immediate necessity of sufficient coolant in the system. Thus, the primary focus should be on the visibility and adequacy of the fluid level.