Vehicle Inspection
Vehicle Inspection
This domain tests the pre-trip inspection you must perform before driving. The exam expects a systematic check of the engine compartment, the walk-around, and the in-cab controls, including air brakes.
Engine and walk-around
Check for fluid leaks, worn belts and hoses, and secure battery connections. Inspect steering linkage, suspension, brake components, lights, reflectors, and tires. The minimum tread depth is 4/32 inch on front steering tires and 2/32 inch on other tires. Check the coupling, cargo securement, and clearance lights.
In-cab and air-brake checks
Start the engine and check oil pressure, air pressure, and warning lights. Build air pressure, then perform the static and applied leak tests. Test the low-air warning, spring brakes, service brake, parking brake, horn, wipers, and mirrors. Make sure the ABS lamp works.
Worked example
A front steering tire measures 3/32 inch. That fails because the minimum for a front steering tire is 4/32 inch. Moving it to a rear position is not a fix if it is still below 2/32 inch; the tire must be replaced.
After-trip
Report defects that affect safety. Do not sign off a vehicle with a brake, tire, steering, or coupling defect that makes it unsafe to drive.
Traps that cost marks
- Checking only the lights and skipping the leak tests.
- Using the 2/32-inch limit for front steering tires.
- Missing a loose fifth-wheel latch or cargo strap.
- Ignoring an ABS warning lamp.