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Practice test 2 of 10

Illinois CDL — Air Brakes Practice Test 2

The Illinois CDL — Air Brakes knowledge test has 25 questions; you need 20 correct (80%) to pass.

This practice test follows that format: 25 questions, pass with 20 correct. Answer every page, then grade it to see the answers and explanations.

Questions 1–10 of 25

  1. 1.With manually operated drain valves, how often are you responsible for emptying the tanks?
  2. 2.What added delay do air brakes introduce that hydraulic brakes on a car do not?
  3. 3.With the engine off and the foot brake held down on a combination vehicle, air loss should not exceed how much in one minute?
  4. 4.If a leak drains all the air from the brake system, what do the spring brakes do?
  5. 5.During hard braking, what does an antilock braking system (ABS) actually do?
  6. 6.In a dual air system at operating rpm, air pressure should climb from 85 to 100 psi within about how long?
  7. 7.At 55 mph on dry pavement, roughly how much distance does air brake lag add?
  8. 8.On a typical air-brake vehicle, a visible low-air warning must appear before pressure drops below what level?
  9. 9.During inspection, a cracked brake drum becomes a defect once the crack is longer than what?
  10. 10.In freezing weather, what is the specific danger of water left in the air tanks?

0 of 25 answered