CDL AIR BRAKE CERTIFICATION EVALUATION
2026 FULL QUESTIONS WITH SOLUTIONS
◉ If your vehicle has a properly functioning air dual brake system
and a minimum sized air tanks, the air pressure should build from
85 to a 100 psi within_________seconds Answer: " 45 "
Explanation: in dual air systems with minimum size air tanks, the
pressure should build from 85 to 100 psi within 45 seconds.( with
larger air tanks, it can take longer. Check the manufactures
specifications for the expected amount of time) if it takes longer
than it should, there may be a problem with your system that may
cause you to lose air pressure while you're driving.
◉ What is a supply pressure gauge for? Answer: " to show how much
pressure is in the air tanks"
Explanation: the air supply pressure gauge is connected to the air
tank for possibly to both tanks and a dual air tank system. It shows
how much air pressure is in the air tanks.
◉ Your vehicle has a dual air brake system. If a low air pressure
warning comes on for just one of the two systems, what should you
do? Answer: " stop and park safely. Continue only after the system
has been fixed"
,Explanation a dual airbrakes system has two separate airbrakes
systems, each with its own air tanks, houses, lines, etc. Typically, one
system operates the brakes on the rear axles, and the other system
operates the brakes on the front axle. If one of the systems loses air
pressure(causes the low air pressure warning) either the front or
the rear brakes won't work properly. As a result, your vehicles
braking distance will increase. If this happens, stop your vehicle and
get the system fixed.
◉ The service brake system applies? Answer: " The brakes when you
depress the brake pedal during normal driving"
Explanation airbrakes are actually three braking systems in one: the
emergency brake, the parking brake, and the service break. As those
terms suggest, when you depress the brake pedal in normal driving,
it's the service brake system that applies to brakes.
◉ In a vehicle equipped with airbrakes, the brake pedal______________
Answer: " Controls the air pressure applied to the service brakes"
Explanation: the brake pedal controls the amount of air pressure
applied to the service breaks. The harder the pedal is push, the more
air pressure is applied to the brakes.
, ◉ The total stopping distance for airbrakes is longer than that of
hydraulic brakes because of? Answer: " brake lag "
Explanation: when you depress the brake pedal on a vehicle with air
brakes, there will be a lag of about a half second before the air flows
through the lines to reach the brakes. This will add at your total
stopping distance.
◉ I have 55 mph on dry pavement, the air brake lag distance is
about? Answer: " 32 feet"
Explanation: when you do press the brake pedal, it will take perhaps
a half second for the air to reach the brakes. At 50 mph, your vehicle
with travel about 32 feet in the time before the brakes kick in. This
will add to your total stopping distance.
◉ On a long or steep downgrade, once you have reached your 'safe'
speed, brake until you are traveling___________ Answer: " 5 mph
slower "
Explanation: on a steep downgrade, Don't keep applying your brakes
continuously because this might caused them to fade, instead apply
your brakes sparingly as a supplement to engine braking. Select a
'safe' speed. Let your vehicle reach this speed, Break and gently until
you are going 5 mph slower. Then let your speed increase by the
2026 FULL QUESTIONS WITH SOLUTIONS
◉ If your vehicle has a properly functioning air dual brake system
and a minimum sized air tanks, the air pressure should build from
85 to a 100 psi within_________seconds Answer: " 45 "
Explanation: in dual air systems with minimum size air tanks, the
pressure should build from 85 to 100 psi within 45 seconds.( with
larger air tanks, it can take longer. Check the manufactures
specifications for the expected amount of time) if it takes longer
than it should, there may be a problem with your system that may
cause you to lose air pressure while you're driving.
◉ What is a supply pressure gauge for? Answer: " to show how much
pressure is in the air tanks"
Explanation: the air supply pressure gauge is connected to the air
tank for possibly to both tanks and a dual air tank system. It shows
how much air pressure is in the air tanks.
◉ Your vehicle has a dual air brake system. If a low air pressure
warning comes on for just one of the two systems, what should you
do? Answer: " stop and park safely. Continue only after the system
has been fixed"
,Explanation a dual airbrakes system has two separate airbrakes
systems, each with its own air tanks, houses, lines, etc. Typically, one
system operates the brakes on the rear axles, and the other system
operates the brakes on the front axle. If one of the systems loses air
pressure(causes the low air pressure warning) either the front or
the rear brakes won't work properly. As a result, your vehicles
braking distance will increase. If this happens, stop your vehicle and
get the system fixed.
◉ The service brake system applies? Answer: " The brakes when you
depress the brake pedal during normal driving"
Explanation airbrakes are actually three braking systems in one: the
emergency brake, the parking brake, and the service break. As those
terms suggest, when you depress the brake pedal in normal driving,
it's the service brake system that applies to brakes.
◉ In a vehicle equipped with airbrakes, the brake pedal______________
Answer: " Controls the air pressure applied to the service brakes"
Explanation: the brake pedal controls the amount of air pressure
applied to the service breaks. The harder the pedal is push, the more
air pressure is applied to the brakes.
, ◉ The total stopping distance for airbrakes is longer than that of
hydraulic brakes because of? Answer: " brake lag "
Explanation: when you depress the brake pedal on a vehicle with air
brakes, there will be a lag of about a half second before the air flows
through the lines to reach the brakes. This will add at your total
stopping distance.
◉ I have 55 mph on dry pavement, the air brake lag distance is
about? Answer: " 32 feet"
Explanation: when you do press the brake pedal, it will take perhaps
a half second for the air to reach the brakes. At 50 mph, your vehicle
with travel about 32 feet in the time before the brakes kick in. This
will add to your total stopping distance.
◉ On a long or steep downgrade, once you have reached your 'safe'
speed, brake until you are traveling___________ Answer: " 5 mph
slower "
Explanation: on a steep downgrade, Don't keep applying your brakes
continuously because this might caused them to fade, instead apply
your brakes sparingly as a supplement to engine braking. Select a
'safe' speed. Let your vehicle reach this speed, Break and gently until
you are going 5 mph slower. Then let your speed increase by the
