The pre-trip inspection section of the CDL license test covers:
Cab Check/Engine Start
Tractor and Coupling
During the pre-trip inspection, you must show that the vehicle is safe to drive. You will have to walk around the vehicle and point to or touch each item and explain to the examiner what you are checking and why. You will NOT have to crawl under the hood or under the vehicle.
The pre-trip inspection of the engine compartment includes identifying or checking leaks, hoses, oil level, coolant level, power steering level, and belts.
The cab check/engine start pre-trip inspection includes identifying or checking oil pressure gauge, temperature gauge, air gauge, ammeter/voltmeter, heater, defroster, parking brake, hydraulic brake, air brake, service brake, safety belt, mirrors, windshield, emergency equipment, wipers, washers, lights, and reflectors.
The external inspection includes identifying or checking steering box, hoses, and linkage, springs, mounts, shock absorbers, slack adjusters, pushrods, brake chambers, brake hoses and lines, brake drums, brake linings, rims, tires, hub oil seals, lug nuts, spacers, doors, fuel tank, drive shaft, exhaust system, frame, splash guards, doors, ties, and lifts.
The tractor and coupling inspection includes identifying or checking air or electric lines, catwalk or steps, mounting bolts, hitch release lever, locking jaws, 5th wheel skid plate, 5th wheel platform, 5th wheel release arm, kingpin, apron or gap, locking pins, sliding pintle, tongue or drawbar, and tongue storage area.