CDL knowledge test | Questions and answers |
2025/2026
What is the most important reason for "Safety" is the most important reason you inspect your vehicle
doing a vehicle inspection? (2.1.1 why inspect)
What things should you check during a Watch gauges for signs of trouble.
trip?
Use your senses to check for problems (look,listen,smell,and
feel)
Check critical items when you stop : tires, wheels, rims, brakes,
lights, reflectors, electrical connections to trailers.
Name some key steering system parts. steering wheel, tie rod, steering shaft, hydraulic fluid
reservoir, gear box, pitman arm, drag link, steering
knuckle, spindle, steering arm, power steering cylinder
Name some suspension system defects spring hangers that allow movement of axle from
proper position, cracked or broken spring hangers,
missing or broken leaves in any leaf spring, leaking shock
absorbers, air suspension systems that are damaged and
or leaking, any parts of the suspension or frame that is
cracked or broden
What three kinds of emergency Fire extinguisher, spare electrical fuses ( unless equipped
equipment must you have? with circuit breakers), warning device for parked vehicles
(ex. 3 reflective warning triangles or 6 fuses or 3 liquid
burning flares).
What is the minimum tread depth for front You need to be at least 4/32-inch tread depth in every major
tires? For other tires? groove on front tires. You need 2/32 inch on other tires.
No fabric should show through the tread or sidewall (
2.1.3 what to look for)
, Name some things you should check on Go to front of vehicle and check that low beams are on and
the front of your vehicle during the walk both of the four way flashers are working.
around inspection? Push dimmer switch and check that high
beams work Turn off headlights and four
way emergency flashers
Turn on parking, clearance , side-maker, and
identification lights Turn on right turn signal and
start walk around inspection.
What should wheel bearing seals be leaks
checked for?
How many red reflective triangles should 3
you carry?
How do you test hydraulic breaks for Pump the breakdown 3 times. Then apply firm pressure to
leaks? the pedal and hold for 5 seconds. The pedal should not
move.
why should you back toward the driver's so you can see better.
side?
if stopped on a hill, how can you start partly engage the clutch before you take your foot off the
moving without rolling back? brake, put on the parking brake whenever necessary to
keep from rolling back
When backing, why is it important to use a because there are blind spots you can't see
helper?
What's the most important hand signal that STOP
you and the helper should agree on?
what are the two special conditions where before starting down a hill, before entering a curve
you should downshift?
when should you downshift automatic when going down grades
transmissions?
Retarders keep you from skidding FALSE. When your drive wheels have poor traction, the
when the road is slippery. True or retarder may actually CAUSE them to skid and should be
False? turned off whenever the road is wet, icy, or snow covered
what are two ways to know when to shift? Use engine speed (rpm) or road speed (mph)
how far ahead does the manual say you 12-15 seconds ahead
should look?
what are two main things to look for Traffic and road conditions
ahead?
what's your most important way to see mirrors
2025/2026
What is the most important reason for "Safety" is the most important reason you inspect your vehicle
doing a vehicle inspection? (2.1.1 why inspect)
What things should you check during a Watch gauges for signs of trouble.
trip?
Use your senses to check for problems (look,listen,smell,and
feel)
Check critical items when you stop : tires, wheels, rims, brakes,
lights, reflectors, electrical connections to trailers.
Name some key steering system parts. steering wheel, tie rod, steering shaft, hydraulic fluid
reservoir, gear box, pitman arm, drag link, steering
knuckle, spindle, steering arm, power steering cylinder
Name some suspension system defects spring hangers that allow movement of axle from
proper position, cracked or broken spring hangers,
missing or broken leaves in any leaf spring, leaking shock
absorbers, air suspension systems that are damaged and
or leaking, any parts of the suspension or frame that is
cracked or broden
What three kinds of emergency Fire extinguisher, spare electrical fuses ( unless equipped
equipment must you have? with circuit breakers), warning device for parked vehicles
(ex. 3 reflective warning triangles or 6 fuses or 3 liquid
burning flares).
What is the minimum tread depth for front You need to be at least 4/32-inch tread depth in every major
tires? For other tires? groove on front tires. You need 2/32 inch on other tires.
No fabric should show through the tread or sidewall (
2.1.3 what to look for)
, Name some things you should check on Go to front of vehicle and check that low beams are on and
the front of your vehicle during the walk both of the four way flashers are working.
around inspection? Push dimmer switch and check that high
beams work Turn off headlights and four
way emergency flashers
Turn on parking, clearance , side-maker, and
identification lights Turn on right turn signal and
start walk around inspection.
What should wheel bearing seals be leaks
checked for?
How many red reflective triangles should 3
you carry?
How do you test hydraulic breaks for Pump the breakdown 3 times. Then apply firm pressure to
leaks? the pedal and hold for 5 seconds. The pedal should not
move.
why should you back toward the driver's so you can see better.
side?
if stopped on a hill, how can you start partly engage the clutch before you take your foot off the
moving without rolling back? brake, put on the parking brake whenever necessary to
keep from rolling back
When backing, why is it important to use a because there are blind spots you can't see
helper?
What's the most important hand signal that STOP
you and the helper should agree on?
what are the two special conditions where before starting down a hill, before entering a curve
you should downshift?
when should you downshift automatic when going down grades
transmissions?
Retarders keep you from skidding FALSE. When your drive wheels have poor traction, the
when the road is slippery. True or retarder may actually CAUSE them to skid and should be
False? turned off whenever the road is wet, icy, or snow covered
what are two ways to know when to shift? Use engine speed (rpm) or road speed (mph)
how far ahead does the manual say you 12-15 seconds ahead
should look?
what are two main things to look for Traffic and road conditions
ahead?
what's your most important way to see mirrors
