Traffic Laws

Study questions with answers

2 sample Traffic Laws questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.

1. 1. In the applied-pressure leak test with the foot brake held down, a single vehicle should not lose more than how much in one minute?

   Correct answer: Three psi.

   With the system charged, engine off and the foot brake fully applied for a minute, a single vehicle should not lose more than three psi (four psi for a combination); more than that means leaks to fix before driving.

   Source: Section 5.3.3 - Final Air Brake Check (air leakage)

2. 2. According to the manual, what is the most common brake defect found during roadside inspections?

   Correct answer: Brakes that are out of adjustment.

   Brakes that have fallen out of adjustment are what inspectors turn up most often at the roadside, which is exactly why the slack adjusters deserve a check.

   Source: Section 5.3.2 - Walk-around Inspection