You must take an air brakes knowledge test to become licensed to operate a vehicle that is equipped with air brakes, including an air over hydraulic braking system.

Rust around wheel nuts can indicate that they are loose. If you observe rust, check the tightness of the nuts.

If you are turning to avoid a hazard, do not apply the brakes while you are turning. This could easily lock the wheels and create a skid.

Defects in an exhaust system are very dangerous because they can cause poisonous fumes to enter the cab or sleeper berth.

Stopping is not always the most effective response to a hazard. You can usually turn out of the path of a hazard more quickly than you can come to a complete stop. However, swerving is not without its hazards, as it may result in a rollover in a vehicle that is either top-heavy or pulling multiple trailers.

Before adding coolant to a system without a recovery or overflow tank, you must turn the engine off and wait until it cools. Use gloves or a thick cloth to protect your hands. To release the pressure seal, turn the radiator cap slowly to the first stop.

Pre-trip inspections should be conducted in the same way every time. This will reinforce the steps, making it less likely that you will forget to inspect something important.

You should always slow to a safe speed before entering a curve. Slowing while within the curve could cause a skid.

It is essential to safety that a driver inspects coupling before starting a trip. Trailer coupling on a double or triple combination can be tested by pulling against the pin of the second semi-trailer.

When a brake pedal is pressed and the S-cam is turned, the S-cam presses the brake shoes against the inside of the brake drum. This causes friction and will cause the vehicle to slow.

When inspecting a vehicle equipped with power steering, you should inspect the hoses, pumps, and fluid levels. Specifically check the hoses for leaks.

There are several reasons why driving at night is more difficult than driving during the day. It is more difficult for drivers to see hazards, the glare of headlights can affect drivers' vision, and there are more fatigued drivers on the road.

To reduce the risk of developing aggressive driving behavior, you should take measures to manage your stress. One strategy to do this is to simply take a deep breath and accept your circumstances if you realize you will be late to your destination.

If a heavy load prevents your vehicle from keeping up with the speed of other traffic, you should stay in the right lane.

Because you can't see everything behind you, backing is always dangerous and should be avoided whenever possible. Choose parking spaces from which you can pull forward when you leave.

To avoid engaging in dangerous and aggressive driving behavior, you should relax and accept any delays that arise throughout a trip. To help avoid the stress of arriving late to a destination, plan for likely delays when planning your drive.

Regrooved, recapped, or retreaded tires are prohibited from use on the front wheels of a bus.

The trailer hand valve, also called the trolley valve or Johnson bar, is used to work the trailer brakes. It should be used only to test the brakes.

When inspecting the fifth wheel before a trip, you should ensure that the release arm is properly seated and the safety latch or lock is engaged. All components should be present and in proper working condition.

If equipped, ABS is in addition to a vehicle's normal braking system and does not increase or decrease the braking power of any other system. ABS only activates when a vehicle's wheels are about to lock.