Vehicle Systems, Inspection, and Maintenance
What the exam tests
Vehicle Systems, Inspection, and Maintenance tests your ability to recognize defects in brakes, tires, lights, steering, suspension, and electrical systems before they become roadside failures.
Core rules
- Build air pressure to governor cut-out, then check for excessive leakage with the engine off and brakes released.
- Know that a low-air warning must activate before pressure falls too low, and spring brakes apply automatically at a low-pressure threshold.
- Check tire tread, sidewalls, inflation, lug nuts, and dual spacing. Look for cracks, bulges, and exposed cord.
- Test lights, horn, wipers, mirrors, steering play, suspension parts, exhaust, and coupling.
- Do not rely on ABS to prevent skids; ABS helps steering control but does not increase traction.
Worked example
With the engine off and brakes released, the air gauge drops from 100 to 92 psi in one minute. That loss exceeds the allowable leakage rate for the test, so the driver should identify the leak and not dispatch the vehicle. A slow leak can become a brake emergency on a downgrade.
Traps that cost marks
Checking only lights during a pre-trip, ignoring tire damage, skipping brake adjustment checks, and assuming ABS means normal braking can be delayed. Maintenance defects must be fixed, not logged and forgotten.
Key idea
A defect found on the pre-trip is a repair decision, not a driving challenge.