Which aspect is not typically part of a vehicle's brake system inspection?

The aspect that is not typically part of a vehicle's brake system inspection is assessing tire tread depth.

Brake system inspections focus specifically on components that are directly related to the vehicle's braking capabilities. This includes checking the integrity of the brake lines to ensure there are no leaks or weaknesses that could lead to brake failure. Verifying the illumination of the brake lights is also crucial, as functional brake lights communicate to other drivers when a vehicle is slowing down or stopping, playing a vital role in safety. Additionally, examining the thickness of the brake pads is essential to determine if they are worn down and require replacement, as insufficient pad thickness can impair braking performance.

In contrast, while tire tread depth is crucial for overall vehicle safety and handling, it falls under tire inspection rather than the brake system itself. Adequate tire tread affects traction and stability but does not directly pertain to the functionality of the brake system components.