What must drivers with hydraulic brake systems inspect at a brake check stop?

Inspecting brake pedal pressure at a brake check stop is crucial for drivers with hydraulic brake systems. This inspection helps confirm that the braking system is functioning properly. Adequate brake pedal pressure is indicative of a well-maintained hydraulic system, where the fluid is effectively transferring force from the driver's foot to the brake components. If the brake pedal feels too soft or goes to the floor without resistance, it suggests a potential issue such as low brake fluid, air in the system, or a leak. Thus, ensuring proper brake pedal pressure is fundamental for vehicle safety and effective braking performance.

While engine oil level, windshield wipers, and tire treads are also important for overall vehicle maintenance, they do not directly relate to the immediate and critical function of the hydraulic braking system. Therefore, focusing on brake pedal pressure is the most relevant action at a brake check stop for ensuring safe driving.