Ontario DZ Exterior Inspection Practice Exam

A major defect in the hydraulic brake system is indicated by the fluid level being less than 1/4 full. This is critical because hydraulic brake systems rely on the proper amount of brake fluid to ensure that the brakes function effectively. When the fluid level drops below this threshold, it can lead to insufficient pressure being generated within the braking system, resulting in a potential failure to stop the vehicle safely. Low brake fluid levels can also indicate leaks or other issues within the system that need urgent attention.

Maintaining the brake fluid at an appropriate level is essential for safe braking performance. If the fluid level is at minimum, it may still be acceptable temporarily, but it certainly doesn't indicate a healthy system. Conversely, if the fluid level is at maximum, this indicates no immediate concern. Therefore, the critical threshold for fluid levels that pose a major risk is when it is less than 1/4 full, necessitating immediate inspection and potential service to ensure safe operation of the vehicle.