Tractor trailer inspection procedures start with the inspector instructing the driver to shut down the vehicle's engine, put the vehicle in neutral and take his foot off the brake. A technician places blocks between the tires or axles. The inspector then examines the driver's credentials, which typically include an up-to-date medical certificate, driver's license and registration, citizenship status and a record of duty status including at least seven days of mileage and work records.
The inspector then checks for any hazardous materials and, if they are present, ensures that the vehicle is approved to carry them. He then determines that there are no leaks or spills in the vehicle and that all cargo is secured and marked appropriately.
Next, the inspector checks the steering lash and column and ensures that all headlights, tail lights, hazard lights and turn signals work properly. He examines the windshield for cracks and the windshield wipers for proper performance.
The inspector also looks under the vehicle to check the steering system, front suspension, front brakes and front axle. He checks the wheels, rims, tires, fuel tank and exhaust on both sides of the vehicle as well as the suspension, brakes and frame.
The inspector then checks the brake adjustment and the movement of the fifth wheel. If any signs of air leaks are present, he instructs the driver to bring the engine's pressure to 80 pounds per square inch and test for any sudden drops that would cause the vehicle to fail inspection. He checks the low air pressure warning device, tractor protection valve, emergency brakes and speed limiter, if applicable. He then completes the paperwork indicating a passed or failed inspection.