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Texas CDL Air Brakes Practice Test
Practice mode
Question
1
of 25
QUESTION 1 / 25
Which action should be avoided when descending a steep hill?
Choose one answer below.
A
Shifting to a lower gear
✓
B
Riding the brake continuously
✓
C
Using engine braking
✓
D
Maintaining a safe speed
✓
QUESTION 2 / 25
How often should air brake system checks be performed?
Choose one answer below.
A
Once a month
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B
Every pre-trip inspection and periodically during travel
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C
Only during vehicle servicing
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D
Daily only for long-haul trips
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QUESTION 3 / 25
What does the air compressor governor control?
Choose one answer below.
A
The temperature of the air
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B
When the air compressor pumps air
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C
The volume of air in the tank
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D
The speed of the vehicle
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QUESTION 4 / 25
What is the first step to check the free play of manual slack adjusters on s-can brakes?
Choose one answer below.
A
Park your vehicle on an incline
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B
Release the parking brake and go to the nearest service station
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C
Park on a level ground and chock the wheels
✓
D
Check the brake fluid levels in the system
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QUESTION 5 / 25
In a vehicle with dual parking control valves, what is a primary benefit?
Choose one answer below.
A
The ability to monitor air pressure
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B
Improved brake efficiency
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C
Increased safety in parking
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D
The ability to move slightly without releasing the springs
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QUESTION 6 / 25
What component prevents air from escaping the tanks if the air compressor develops a leak?
Choose one answer below.
A
Pressure relief valve
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B
One way check valve
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C
Brake governor
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D
Relay valve
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QUESTION 7 / 25
What is the name of the valve that controls the flow of air in the brake system?
Choose one answer below.
A
The control valve
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B
The brake valve or treadle valve
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C
The pressure relief valve
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D
The emergency brake valve
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QUESTION 8 / 25
What can excessive brake wear lead to in terms of vehicle performance?
Choose one answer below.
A
Improved acceleration
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B
Increased stopping distances
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C
Better fuel efficiency
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D
Higher reliability
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QUESTION 9 / 25
What is the correct technique for stab braking?
Choose one answer below.
A
Press down on the brakes and hold
✓
B
Brake as hard as possible, release when wheels lock, and reapply when wheels start rolling again
✓
C
Ease off the brake pedal gradually
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D
Use engine braking primarily
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QUESTION 10 / 25
What is the most common type of foundation brakes found on heavy vehicles?
Choose one answer below.
A
Disk brakes
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B
S-can drum brakes
✓
C
Hydraulic brakes
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D
Ventilated disc brakes
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QUESTION 11 / 25
What effect does increased air pressure have on the braking system?
Choose one answer below.
A
It reduces stopping distance
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B
It decreases braking power
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C
It creates excessive heat
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D
It has no effect on braking
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QUESTION 12 / 25
What does proper air brake maintenance prevent?
Choose one answer below.
A
Fuel consumption increase
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B
Brake component wear
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C
Air system freezing
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D
Vehicle overheating
✓
QUESTION 13 / 25
What does "stab braking" involve?
Choose one answer below.
A
Applying the brakes firmly until the vehicle stops.
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B
Pressing the brake pedal hard, releasing it during wheel lock, and re-applying.
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C
Gradually reducing speed without fully pressing the brakes.
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D
Using the engine to slow down the vehicle.
✓
QUESTION 14 / 25
Which brake application helps maintain vehicle control during an emergency?
Choose one answer below.
A
Gradual braking
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B
Stab braking
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C
Pump braking
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D
Soft braking
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QUESTION 15 / 25
How can you determine if the brake chambers are functioning properly?
Choose one answer below.
A
If the brakes apply fully and release without air leaks
✓
B
If there is a consistent high-pitched noise
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C
If the air pressure gauge fluctuates
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D
If the vehicle shakes during braking
✓
QUESTION 16 / 25
How can you determine if the air brake system is functioning properly?
Choose one answer below.
A
By checking the air pressure gauge
✓
B
By inspecting the visual appearance of parts
✓
C
By checking the sound of the compressor
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D
By testing the vehicle speed
✓
QUESTION 17 / 25
To check if slack adjusters need adjustment, what should you do?
Choose one answer below.
A
Activate the emergency brake
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B
Release both service and parking brakes
✓
C
Check the brake light indicators
✓
D
Inspect the brake pads visually
✓
QUESTION 18 / 25
What should you do to check the slack adjusters on s-can brakes?
Choose one answer below.
A
Wear thick protective gloves and use a wrench
✓
B
Pull hard on each adjuster
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C
Inspect visually without touching
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D
Use a measuring tool to assess slack
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QUESTION 19 / 25
What is one of the key factors to prevent brake component wear?
Choose one answer below.
A
Performing regular maintenance
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B
Increasing stopping distance
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C
Encountering hilly terrain
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D
Utilizing heavy loads
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QUESTION 20 / 25
How can you tell if your air brakes are engaging properly during a test?
Choose one answer below.
A
By checking for visible smoke from the brake components
✓
B
By checking for the proper feel and response from the brake pedal
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C
By measuring the temperature of the brake drums
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D
By the amount of air pressure in the tires
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QUESTION 21 / 25
What is the recommended method for testing service brakes?
Choose one answer below.
A
Depress the brake pedal while stationary and check response.
✓
B
Release the parking brake, move forward slowly, and depress brakes.
✓
C
Activate the emergency stop button.
✓
D
Use a diagnostic tool for braking system evaluation.
✓
QUESTION 22 / 25
How do you recognize a trailer air supply control valve?
Choose one answer below.
A
It's usually painted black
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B
It's usually marked with a red knob
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C
It has an audible alarm
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D
It's usually located near the ignition
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QUESTION 23 / 25
What should you do when driving down a long steep hill?
Choose one answer below.
A
Keep constant pressure on the brake pedal
✓
B
Release the brake when you are 5 mph below your safe speed
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C
Shift to a lower gear and maintain brake pressure
✓
D
Never use the brakes to avoid overheating
✓
QUESTION 24 / 25
What should you avoid doing when stopping with air brakes?
Choose one answer below.
A
Gradually applying the brakes
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B
Utilizing the engine brake first
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C
Avoiding sudden or harsh maneuvers
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D
Using the trailer brakes earlier
✓
QUESTION 25 / 25
How can you visually inspect air brake components?
Choose one answer below.
A
Look for visible light shining through the brake housing
✓
B
Look for cracks, leaks, and wear on hoses and connections
✓
C
Check for color changes in the brake fluid
✓
D
Measure the thickness of the brake pads
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