What should be checked in the brake system during pre-trip inspections?

In a pre-trip inspection, the brake system is crucial for the safe operation of a commercial vehicle, and checking the air pressure and responsiveness of the brakes is essential. Proper air pressure ensures that the braking system operates effectively and can apply sufficient force to stop the vehicle in a timely manner. A lack of adequate air pressure may indicate leaks or other issues that could compromise the braking system's performance.

Additionally, assessing the responsiveness of the brakes allows the driver to determine if they engage smoothly and effectively when applied. Any delay or unusual feedback may signal a problem that needs to be addressed before the vehicle is operated. Ensuring both the air pressure and responsiveness are within acceptable limits is vital for safety on the road.

Other options, while they may involve aspects of brake maintenance or inspection, do not directly reflect the immediate checks necessary for ensuring safe operation prior to driving. Factors like the color of brake fluid, brake size, and the age of components can be important for long-term maintenance but are not typically evaluated during the immediate pre-trip inspection.