Hydraulic Brake Checks - ONLINE CDL SCHOOL

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Hydraulic Brake Checks

Build confidence with 10 original questions about Hydraulic Brake Checks. Review your answers and explanations after finishing.

Supplemental study practice. This is not a government licensing exam or ELDT certification, and does not replace hands-on training. Follow your state’s current handbook.

1 / 10

During a pre-trip inspection, you check the air leakage rate on a single vehicle after applying the foot brake. What is the maximum air pressure drop allowed in one minute?

No more than five pounds

No more than one pound

No more than three pounds

No more than four pounds

2 / 10

After coming down a steep grade, your brakes are very hot. What should you avoid doing?

Using wheel chocks on a level surface

Driving in a low gear to dry the brakes

Letting the brakes cool before parking

Applying the parking brakes immediately

3 / 10

While descending a long, steep downgrade, what is the correct braking technique to use with air brakes?

Pump the brakes rapidly until you reach the bottom.

Keep steady pressure on the brakes the entire way down.

Apply the brakes hard enough to reduce speed by about 5 mph below your safe speed, then release and repeat as needed.

Use only the engine brake and avoid using the service brakes.

4 / 10

You are inspecting the parking brake on a truck. What is the correct way to test if it will hold the vehicle?

Apply the parking brake and pump the service brake pedal.

Engage the parking brake and rev the engine in neutral.

Engage the parking brake, remove your foot from the service brake, and gently pull forward.

Release the parking brake and try to roll backward.

5 / 10

You are driving a vehicle with air brakes and the low air pressure warning comes on. What should you do?

Ignore the warning if the brakes still feel normal.

Stop and safely park the vehicle as soon as possible.

Continue driving until you reach your destination.

Pump the brakes rapidly to build pressure.

6 / 10

During a hydraulic brake check, after pumping the brake pedal three times and holding it down for five seconds, what should you observe?

The brake pedal should make a hissing sound.

The brake pedal should bounce back up immediately.

The brake pedal should remain firm and not move downward.

The brake pedal should slowly sink to the floor.

7 / 10

When performing a hydraulic brake check, what should you inspect regarding the warning systems?

Check that the warning light stays on at all times.

Verify the warning buzzer sounds when the engine is off.

Make sure the warning systems activate only after a brake failure.

Ensure indicators and warning systems function as specified by the manufacturer.

8 / 10

If you notice a brake drum has a crack longer than half the width of the friction area during inspection, what should you do?

Tighten the wheel nuts and proceed.

Apply grease to the crack and retest.

Continue driving and monitor the crack.

Do not use the vehicle until the drum is replaced.

9 / 10

While inspecting a vehicle with air brakes, you fan off air pressure and notice the low air warning activates at 50 psi. What does this indicate?

The spring brakes will not function.

The warning device is working properly.

The air pressure is too high.

The warning device is not working correctly and should activate before 55 psi.

10 / 10

You are performing a service brake check during your pre-trip inspection. What should you do to verify the brakes are working correctly?

Pump the brakes rapidly and check for warning lights.

Apply the parking brake and check if the vehicle moves.

Press the brake pedal while parked and listen for air leaks.

Pull forward at 5 mph, apply the service brake, and check that the vehicle stops without pulling to either side.

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About the Hydraulic Brake Checks practice quiz

This practice quiz focuses on Hydraulic Brake Checks, listed under CDL Practice — Pre-Trip Inspection. Use it to check what you understand, spot topics to revisit, and connect the material to safe, informed decisions on the road.

Before you begin

Keep your current CDL manual or course notes nearby. Read each prompt carefully and think through why an answer fits, especially when a question describes a vehicle, road, or workplace situation. Licensing rules and procedures can vary, so confirm requirements with current official materials for your state.

After you finish

Review any explanations shown with your results. Note unfamiliar terms or missed concepts, then revisit your manual or course notes before trying again. Use your score to guide study; understanding why an answer is correct matters more than the number alone.

Study note: These quizzes are independent study practice. They are not state licensing exams, official government materials, or ELDT certification, and they do not replace required training.

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