Safe Driving Practices

Study questions with answers

8 sample Safe Driving Practices questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.

1. 1. What is the job of an alcohol evaporator in some air brake systems?

   Correct answer: To reduce the risk of ice forming in the valves in cold weather

   By feeding alcohol into the system, the evaporator lowers the chance of ice forming in air brake valves and other parts during cold weather, since ice can keep the brakes from working.

   Source: Section 5.1.5 - Alcohol Evaporator

2. 2. Why is it important to drain the air storage tanks completely?

   Correct answer: To clear out water and oil that harm the system and can freeze

   Compressed air carries water and a little compressor oil that settle at the bottom of the tank; the water can freeze in cold weather and cause the brakes to fail, so the tanks must be emptied fully.

   Source: Section 5.1.4 - Air Tank Drains

3. 3. Which statement about slack adjusters on vehicles built since 1994 is accurate?

   Correct answer: They are automatic but still have to be checked

   Every vehicle made since 1994 uses automatic slack adjusters; even though they self-adjust during full brake applications, the driver still has to inspect them.

   Source: Section 5.3.2 - Walk-around Inspection

4. 4. Among foundation brakes, which design is the most widely used?

   Correct answer: The s-cam drum brake

   Foundation brakes sit at every wheel, and the s-cam drum brake is by far the most common; wedge and disc types are far less common.

   Source: Section 5.1.8 - Foundation Brakes

5. 5. How is the air compressor usually driven by the engine on an air brake vehicle?

   Correct answer: Through gears or a v-belt

   The compressor takes its power from the engine, linked either through a set of gears or by a v-belt.

   Source: Section 5.1.1 - Air Compressor

6. 6. During the engine compartment step of the inspection, what extra air brake item should you check on a belt-driven compressor?

   Correct answer: The condition and tightness of the compressor drive belt

   When the compressor runs off a belt, the inspection adds a check of that belt's condition and tension; it should be in good shape.

   Source: Section 5.3.1 - Engine Compartment Checks

7. 7. If a truck's air compressor carries its own separate oil supply, what should the driver do before setting out?

   Correct answer: Check the compressor's oil level

   A compressor that holds its own oil, rather than being lubricated by engine oil, needs its oil level checked before you drive.

   Source: Section 5.1.1 - Air Compressor

8. 8. An air brake setup is really a combination of which three separate braking systems?

   Correct answer: Service, parking, and emergency braking systems

   The manual explains that air brakes bring together three systems: the service brakes for normal driving, the parking brakes, and the emergency brakes, which borrow parts of the other two if a failure occurs.

   Source: Section 5 - Air Brakes (Introduction)