What is the correct method to check the service brake operation?

The correct method to check the service brake operation is to perform a test by applying the brakes while the vehicle is in motion. This technique allows the driver to assess the effectiveness, responsiveness, and any potential issues with the braking system in real-time.

When brakes are applied while the vehicle is moving, the driver can feel how the brakes respond, checking for any unusual noises, pulling to one side, or delayed stopping. This dynamic test is essential to ensure the safety and reliability of the brakes before embarking on a journey.

The other methods, while important in different contexts, do not provide a comprehensive assessment of the service brake operation. A visual inspection of the brake components is crucial for identifying obvious wear or damage, but it does not reveal how the brakes perform under operational conditions. Tightening brake fittings is necessary for maintaining the brake system's integrity, yet it does not address the functional performance of the brakes. Lastly, measuring brake fluid levels is part of brake maintenance, but merely checking fluid levels does not guarantee that the brakes are functioning properly when engaged. Thus, testing the brakes while the vehicle is in motion provides the most effective evaluation of the service brake system.