Practice question

A low air pressure warning signal should activate:

  1. When tank pressure falls below 120 psi.
  2. When tank pressure falls below 55 psi.
  3. When tank pressure falls below 10 psi.
  4. When tank pressure falls below 5 psi.

Answer: B — When tank pressure falls below 55 psi.

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: Texas CDL Air Brakes Test 2 →