Pre-Trip Inspection for the CDL Exam

Common failure modes

These are the patterns that cause most candidates to lose marks on this topic. Recognising them in advance is half the work.

• !Silent inspection — examiners cannot score what they cannot hear
• !Wrong sequence — the standard test follows engine compartment → in-cab → lights → walk-around → coupling → air-brake check
• !Skipping the in-cab check (mirrors, gauges, defroster, horn)
• !Forgetting to return to the cab for the air-brake static and applied tests after walk-around

Study tips

• 1Use the say-it-to-pass-it bookend: announce the part, describe what you're checking for, report the result.
• 2Drill the 7 sections in order: engine, cab, lights, walk-around (4-side), coupling, air-brake check, lights again.
• 3Memorize the 100+ part names — examiners deduct points for "this thing" or "the thingy".
• 4Practice with a 30-minute timer — examiners want efficient, deliberate pace, not a museum tour.

Sample CDL Pre-Trip Inspection questions

These sample items mirror the format and difficulty of real CDL questions. Practice with thousands more on the free Koydo question bank.

1. 1

   During pre-trip, slack adjusters should not move more than:

   • A1/4 inch
   • B1/2 inch
   • C1 inchCorrect
   • D2 inches
   Why this answer?

   Manual slack adjusters should not move more than 1 inch when pulled by hand. More than that indicates excessive brake-shoe wear and requires adjustment before operating the vehicle.