Ohio CDL Air Brake Removal Exam

Ohio CDL Air Brake Removal Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2025|2026 Q&A | Instant Download Pdf

• What is the main reason for removing the Air Brake restriction from a

CDL?

• To drive manual transmission vehicles
• To operate vehicles with hydraulic brakes only
• To operate vehicles equipped with full air brakes
• To operate only automatic transmission trucks

Rationale: The air brake restriction is removed so a driver can legally operate

vehicles using a full air brake system.

• Which of the following systems uses compressed air for braking?
• Hydraulic brake system
• Vacuum brake system 1 / 4

• Air brake system
• Friction brake system

Rationale: Air brake systems rely on compressed air to apply and release

brakes.

• What component stores compressed air?
• Brake chamber
• Compressor governor
• Air tanks
• Relay valve

Rationale: Air tanks store compressed air for use in braking and other

pneumatic systems.

• What does the air compressor do?
• Applies the brakes
• Pumps air into the air storage tanks
• Releases the parking brakes
• Measures air pressure

Rationale: The compressor fills the air tanks with compressed air for braking

operations.

• / 4

• How is the air compressor controlled?
• Manually by the driver
• Automatically by the governor
• By the brake pedal
• Through the dashboard switch

Rationale: The governor regulates the compressor’s cut-in and cut-out

pressure automatically.

• When does the governor cut-out occur?
• When pressure drops below 85 psi
• When pressure drops below 90 psi
• When air pressure reaches around 125 psi
• When air pressure exceeds 150 psi

Rationale: The governor stops the compressor around 120–125 psi to

prevent over-pressurization.

• What is the typical governor cut-in pressure?
• 60 psi
• 100 psi
• 130 psi
• 150 psi

Rationale: The compressor resumes pumping air when pressure falls to about

100 psi. 3 / 4

• What helps remove water and oil from the air tanks?
• Foot valve
• Air tank drain valves
• Slack adjusters
• Service brakes

Rationale: Drain valves are used to remove moisture and oil to prevent

freezing and corrosion.

• How often should air tanks be drained manually if not automatic?
• Weekly
• Monthly
• Daily
• Yearly

Rationale: Air tanks should be drained daily to maintain system performance

and safety.

• What is the main function of the air dryer?
• Compress air
• Remove moisture and oil
• Store compressed air
• Release brakes
• / 4