CDL Air Brakes Test|| 2025 LATEST
UPDATE|| VERIFIED A+
In air brake vehicles, the parking brakes should be used: - ANSWER Any time the
vehicle is parked.
If your antilock braking system is not working, you should: - ANSWER Drive normally,
but get the system serviced soon
Excessive use of the service brakes result in overheating, which can lead to: -
ANSWER Expansion of the brake drums
Your truck or bus has a dual air brake system. If a low air pressure warning comes on
for only one system - ANSWER Stop and safely park. Continue only after the system is
fixed.
The air compressor should stop pumping at _______ psi - ANSWER 125 psi
The use of air brakes on a downgrade is only a supplement to the: - ANSWER Braking
effect of the engine
Your truck has a properly functioning dual air brake system and minimum size air tanks.
The air pressure should build from 85 to 100 psi within _______ seconds. - ANSWER
45 seconds
If your truck or bus has dual parking control valves, you can use pressure from a
separate tank to: - ANSWER Release the spring emergency parking brakes to move a
short distance.
The proper method of braking when going down long and/or steep grades after
selecting the proper gears is to brake until your speed is about _____ miles per hour
below your "safe" speed, and then release your brakes - ANSWER 5 mph
It is not safe to drive a vehicle that has brake drums (or discs) with cracks that are
thinner than the manufactures specifications, generally this will be _____ inch -
ANSWER 1/4 inch thickness
Air breaking takes more time than hydraulic braking because air: - ANSWER Takes
more time to flow through the lines than hydraulic fluid
During normal driving, spring brakes are usually held back by: - ANSWER Air pressure
, Some air brake systems have an alcohol evaporator. What may happen if you don't
keep the unit filled with alcohol? - ANSWER Ice may form in the air storage tanks and
cause the brakes to fail.
The brake system that applies and releases the brakes when the driver uses the brake
pedal is the ________ brake system. - ANSWER Service
Excessive heat in the brakes can cause the - ANSWER Brakes to fade or fail
To test air system brakes, you should: - ANSWER Brake firmly when slowly moving
forwards
You should know your brakes are fading when: - ANSWER You have to push the brake
pedal harder to control speed on a downgrade
The air brake system for a straight truck or bus should not leak at a rate me more than
_____ psi per minute with the engine off and the brakes released - ANSWER 2
The braking power of the spring brakes - ANSWER Depends on the service brakes
being in adjustment
If your truck has a dual air system and one of the systems is low on pressure: -
ANSWER Either the front or rear brakes will not be fully operational
The parking or emergency brakes of the trucks and buses can be legally held on by _
pressure - ANSWER spring
Modern air brake systems are three different systems combined together. They are the
service, parking, and the ________ brakes. - ANSWER emergency
The air supply pressure gauge shows how much pressure - ANSWER Is in the air
tanks
Repeatedly pressing and releasing (fanning) the brake pedal may result in: - ANSWER
The loss of brake air pressure
The air compressor governor controls - ANSWER When air is pumped into the air
storage tanks.
The most common type of foundation brake found on heavy vehicles is the - ANSWER
S-cam drum
You are on a steep downgrade and have reached your "SAFE" speed of 40 mph. You
would apply the service brakes until your speed drops to __ mph. - ANSWER 35 mph
UPDATE|| VERIFIED A+
In air brake vehicles, the parking brakes should be used: - ANSWER Any time the
vehicle is parked.
If your antilock braking system is not working, you should: - ANSWER Drive normally,
but get the system serviced soon
Excessive use of the service brakes result in overheating, which can lead to: -
ANSWER Expansion of the brake drums
Your truck or bus has a dual air brake system. If a low air pressure warning comes on
for only one system - ANSWER Stop and safely park. Continue only after the system is
fixed.
The air compressor should stop pumping at _______ psi - ANSWER 125 psi
The use of air brakes on a downgrade is only a supplement to the: - ANSWER Braking
effect of the engine
Your truck has a properly functioning dual air brake system and minimum size air tanks.
The air pressure should build from 85 to 100 psi within _______ seconds. - ANSWER
45 seconds
If your truck or bus has dual parking control valves, you can use pressure from a
separate tank to: - ANSWER Release the spring emergency parking brakes to move a
short distance.
The proper method of braking when going down long and/or steep grades after
selecting the proper gears is to brake until your speed is about _____ miles per hour
below your "safe" speed, and then release your brakes - ANSWER 5 mph
It is not safe to drive a vehicle that has brake drums (or discs) with cracks that are
thinner than the manufactures specifications, generally this will be _____ inch -
ANSWER 1/4 inch thickness
Air breaking takes more time than hydraulic braking because air: - ANSWER Takes
more time to flow through the lines than hydraulic fluid
During normal driving, spring brakes are usually held back by: - ANSWER Air pressure
, Some air brake systems have an alcohol evaporator. What may happen if you don't
keep the unit filled with alcohol? - ANSWER Ice may form in the air storage tanks and
cause the brakes to fail.
The brake system that applies and releases the brakes when the driver uses the brake
pedal is the ________ brake system. - ANSWER Service
Excessive heat in the brakes can cause the - ANSWER Brakes to fade or fail
To test air system brakes, you should: - ANSWER Brake firmly when slowly moving
forwards
You should know your brakes are fading when: - ANSWER You have to push the brake
pedal harder to control speed on a downgrade
The air brake system for a straight truck or bus should not leak at a rate me more than
_____ psi per minute with the engine off and the brakes released - ANSWER 2
The braking power of the spring brakes - ANSWER Depends on the service brakes
being in adjustment
If your truck has a dual air system and one of the systems is low on pressure: -
ANSWER Either the front or rear brakes will not be fully operational
The parking or emergency brakes of the trucks and buses can be legally held on by _
pressure - ANSWER spring
Modern air brake systems are three different systems combined together. They are the
service, parking, and the ________ brakes. - ANSWER emergency
The air supply pressure gauge shows how much pressure - ANSWER Is in the air
tanks
Repeatedly pressing and releasing (fanning) the brake pedal may result in: - ANSWER
The loss of brake air pressure
The air compressor governor controls - ANSWER When air is pumped into the air
storage tanks.
The most common type of foundation brake found on heavy vehicles is the - ANSWER
S-cam drum
You are on a steep downgrade and have reached your "SAFE" speed of 40 mph. You
would apply the service brakes until your speed drops to __ mph. - ANSWER 35 mph
