Pre-Trip Inspection & Vehicle Safety Checks practice test: free CDL General Knowledge questions

Sample Practice Questions for Pre-Trip Inspection & Vehicle Safety Checks

1. Question 1Ref: 49 CFR 393.95 — Low Air Pressure Warning

   What is the minimum air pressure at which the low air pressure warning device must activate?

   A60 psiB55 psiC45 psiD50 psi
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   Correct Answer
   D. 50 psi

   The low air pressure warning must come on before air pressure falls below 55 psi (or one half the compressor cut-out pressure, whichever is greater). At or below 50 psi, the spring brakes should automatically apply. Never drive with the warning light or buzzer on.

2. Question 2Ref: 49 CFR 392.7(a) — Equipment, Inspection and Use

   During a pre-trip inspection, which of the following items should you check on the steering system?

   AFluid level, play, and mounting boltsBOnly the power steering pump beltCThe brake pedal return springDThe gear selector linkage
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   Correct Answer
   A. Fluid level, play, and mounting bolts

   A thorough steering system inspection includes checking power steering fluid level, ensuring no more than 2 inches of play (10 inches at the steering wheel), and verifying that all mounting bolts are secure. A loose steering system can lead to loss of vehicle control.

3. Question 3Ref: 49 CFR 392.7(a) — Coupling Devices

   What should you check when inspecting the coupling devices during a pre-trip?

   AOnly the kingpin lock jawBJust the fifth wheel lubricationCThe trailer door hingesDKingpin, locking mechanism,Mounting bolts, and apron
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   Correct Answer
   D. Kingpin, locking mechanism,Mounting bolts, and apron

   Coupling device inspection includes verifying the kingpin is locked in the fifth wheel jaws, checking that locking mechanism is engaged, inspecting mounting bolts for tightness, and ensuring there is no gap between the apron and the fifth wheel plate. A failed coupling can result in a dropped trailer.