Air Brake Endorsement Practice Test

To check the air pressure in a vehicle's air brake system, a driver:

How does ABS improve braking performance?

A spring brake control valve is normally:

What is the role of the alcohol evaporator in the air brake system?

What should be used to prevent vehicle movement during an air brake inspection?

To test the low air warning device, the ignition switch must be turned on and air pressure must be:

What type of brake is used in both emergency and parking situations?

What is the maximum allowable air loss rate for a combination vehicle during an applied pressure test?

A vehicles brakes must do more wok when:

What component combines service brake and parking brake functionality?

A governor controls air compressor

The air that exhausts from an air brake system can carry: 

Why is it important to regularly inspect the slack adjusters?

How does an "S" cam brake apply the brakes?

What is the purpose of an anti-compound system in air brakes?

Air compressors are powered directly by the engine or by using:

How often should drivers inspect slack adjusters?

The compressed air in an air brake system is stored in:

When inspecting the air compressor, the driver must look for:

What happens if the air compressor fails during operation?

What is the function of the governor in an air brake system?

Why is it important to monitor air tank pressure gauges?

When inspecting the air compressor drive belt, the driver must look for:

What is the normal operating pressure range for most air brake systems?

The type of air brake components on most large commercial vehicles are either: 

How should a driver check for air leaks in the system during a static test?

A properly functioning air brake system:

High brake temperatures can results from:

The air loss rate on a towing vehicle with two or more trailers must not exceed: 

What should you observe when testing the emergency brake system?

Which device adds alcohol vapor to prevent freezing in the air brake system?

Why is it critical to check air hoses and fittings during a pre-trip inspection?

How does a parking brake control valve operate?

When inspecting the foundation brake components, the driver must look for:

What is the normal range for air compressor cut-out pressure?

What is the purpose of the double-check valve in air brake systems?

At what point does the air compressor governor cut in?

'S' cam brake components include:

What is the purpose of the service line in an air brake system?

Why is it important to check ABS warning lights during a trip?

The part inside a spring brake chamber can be hazardous if the:

When an air brake system is defective you must:

Anti-lock braking system (ABS) use warning indicator lights to indicate:

What should you do when the low air-pressure warning device activates?

Using anti-lock braking systems (ABS) to prevent the wheels from locking:

A vehicle's brakes must do more work when:

What component is used to determine air tank pressure levels? 

When testing air pressure build-up time, pressure must build from 587 to 690 kPa (85 to 100 psi) within:

While draining a vehicle air tanks, the driver must watch the:

Inspecting the air tanks, the driver must look for:

How often should spring brakes be checked for proper operation?

How can drivers check slack adjusters during a pre-trip inspection?

What is the primary purpose of air brake systems on large commercial vehicles?

What must a driver check during an air brake system inspection?

When a vehicle's brakes do not comply with the Ontario Highway Traffic Act and regulations:

Air compressors are mounted directly onto the engine or by using:

Air compressors:

A brake having an exposed pushrod is out of adjustment when:

What is the function of the emergency brake system? 

What is the purpose of brake drums in the air brake system?

Why do vehicle service brakes failed to apply, emergency brakes can be applied by using the:

Which system ensures braking ability even if one circuit fails?

What is the purpose of the relay emergency valve in trailer systems?

To test the spring brakes, the driver should apply them and attempt to move the vehicle by:

Why is it critical to check air hoses during cold weather?

What component prevents over-pressure in the air brake system?

Driving a vehicle with an air brake system that is outside the normal operating pressure range is:

What is the primary function of the supply (wet) tank in an air brake system?

The ability of the brakes to stop a vehicle:

What might indicate a damaged brake chamber diaphragm?

A trailer supply valve is usually:

What component ensures balanced braking in a dual-circuit system?

What is the role of the tractor protection valve?

An air dryer removes moisture, which is expelled when the:

What is the role of a relay valve in an air brake system?

Air brake chamber pushrod stroke is the result of:

What is the purpose of the tractor protection valve? 

To test air pressure build-up-time, the engine must be running at:

What is the purpose of brake linings in drum brakes? 

The normal operating pressure range for air brake system is:

When air brakes are applied or released, the brakes will respond:

Trailer spring brakes must apply automatically when the:

When air brake system pressure drops below 414 kPa (60psi), the spring brakes:

What is the function of the air dryer’s purging system?

How should a driver verify air pressure build-up time? 

Repair and re-adjustment of all types of air brakes may be performed by:

What is the most common type of foundation brake system used in commercial vehicles?

The brake pedal in air brake system is used to:

Which air brake system component prevents air loss when disconnected from a trailer?

Disk brake components includes:

When should you drain the air tanks?

When inspecting visible air brake hoses and tubes, drivers must check for:

A tractor protection valve:

Spring brake chambers:

What is the purpose of the air compressor governor?

What is the purpose of the "wig wag" low air-pressure warning device?

To prevent vehicle movement during an inspection of the air brake system, a driver should use:

What type of braking system is required for medium-duty vehicles with air-over-hydraulic brakes?

What action should be taken if brake fade is detected?

A tractor protection valve is defective if the trailer supply valve is closed (pulled out) and air exhausts from the:

Safety valves prevent:

What should you inspect on brake hoses and tubes during an air brake check?

What happens if the air pressure in the primary circuit drops below safe levels?

What is the minimum allowable air pressure for a tractor-trailer combination before driving?

What happens when moisture accumulates in the air brake system?

How can drivers test the tractor protection system?

Brake fade can result:

What should a driver do when the air pressure drops below 552 kPa (80 psi)?

How do anti-lock braking systems (ABS) enhance vehicle safety?

Manually-operated front wheel limiting valves are:

Which factor can lead to brake fade?

What does an air brake application pressure gauge indicate?

hy are "S" cam brakes commonly used in commercial vehicles?

Why is it essential to inspect brake drums regularly?

Wedge brake components include:

How can drivers check for proper brake adjustment during a pre-trip inspection?

What is the allowable air pressure drop during a static brake test for a single vehicle?

What is the purpose of the one-way check valve in an air brake system?

What should you do if the air compressor takes more than 2 minutes to build pressure from 85 psi to 100 psi?

The low air warning device must active before air pressure drops to:

The trailer hand valve is used to:

Air compressor cut-in pressure must be less than:

What is the effect of overloading a vehicle on the brake system?

Drivers who are certified to re-adjust air brakes may do so on:

What is the purpose of an air dryer in an air brake system?

Which type of foundation brake uses a disc-shaped rotor and caliper? 

Each air brake chamber style, type and size has a specific:

An air compressor governor should cut-in approximately 138 to 173 kPa (20-25 psi):

Brakes convert the energy of a moving vehicle into:

What is the first tank that compressed air enters in an air brake system called?

A trailer with 'spring brake' priority allows the trailer spring brakes to release before:

When a driver finds a brake that is out of adjustment:

When the air pressure in the trailer supply line drops below 414 kPa (60 psi):

When inspecting the brake chambers on each side of steering axle, the driver must ensure that slack adjusters are :

What should be done if the low-pressure warning activates while driving?

Air brake systems must comply with the Ontario Highway Traffic Act and Regulations:

If a vehicle moves while the spring brakes are applied, the vehicle has:

What is the primary safety function of spring brakes?

Every reliable method for inspecting brake adjustment on a brake having an exposed pushrod is:

When a trailer service brakes fail to apply, the trailer spring brakes can applied by using:

How are air brakes applied in a trailer during an emergency?

What happens if the pushrod stroke exceeds its adjustment limit?

How often should air tanks be drained in humid conditions?

Why is it essential to avoid over-adjusting slack adjusters?

At what pressure must the low air-pressure warning device activate?

When trial trailer couplers or 'glad hands' are cross-connected:

What should be done if the parking brake fails to engage?

The brake system on most large commercial vehicle use:

What safety feature automatically applies the parking brakes if air pressure is too low? 

What is the purpose of the dual-service air tanks in an air brake system?

What should a driver observe during a service brake application test?

An air tank drain valve that fails to function:

The air loss rate on a single vehicle (bus, tractor or truck) must not exceed :

When brake chamber pushrod stroke exceeds the adjustment limit:

When inspecting the brake chambers, the driver must look for:

What is the purpose of the quick-release valve in an air brake system?

To test the tractor protection valve, the driver must check for air exhausting from the:

Trailer couplers or 'glad hands' are usually:

How should drivers test the low-pressure warning system?

What is spring brake chamber has been disabled by a "caging bolt" or other mechanism:

When air loss from air brake system exceeds the prescribed limits:

Drivers must be careful when conducting an inspection of the air brake system to avoid:

How can drivers recognize a failing air compressor?

Why should air tanks be drained regularly?

When conducting an inspection of the air brake system, the vehicle should be parked currently on a:

What is the function of the modulator valve in ABS?

What is the function of a quick-release valve?

When measuring the applied pushrod stroke on brakes having exposed pushrods, air pressure must be between   :

When a low air pressure warning device activates, the driver must:

Anti-lock braking systems (ABS):

When inspecting brake drums and rotors, the driver must look for:

Alcohol evaporates may be used to:

What component helps control brake shoe movement in drum brakes?

Air tanks must be drained regularly because: