Air Brake Endorsement Practice Test

A vehicles brakes must do more wok when:

Why is it important to regularly inspect the slack adjusters?

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

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

Air tanks must be drained regularly because:

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

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

What component combines service brake and parking brake functionality?

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

How often should spring brakes be checked for proper operation?

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

The ability of the brakes to stop a vehicle:

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

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

Manually-operated front wheel limiting valves are:

What is the primary safety function of spring brakes?

High brake temperatures can results from:

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

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

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

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

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

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

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

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

Trailer spring brakes must apply automatically when the:

What is the function of the emergency brake system? 

Safety valves prevent:

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

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

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

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

What is the function of a quick-release valve?

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

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

Air compressor cut-in pressure must be less than:

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

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

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

When an air brake system is defective you must:

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

What happens if the pushrod stroke exceeds its adjustment limit?

Why should air tanks be drained regularly?

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

When brake chamber pushrod stroke exceeds the adjustment limit:

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

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

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

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

A tractor protection valve:

'S' cam brake components include:

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

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

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

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

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

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

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

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

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

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

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

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

Inspecting the air tanks, the driver must look for:

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

Brakes convert the energy of a moving vehicle into:

What component is used to determine air tank pressure levels? 

What is the purpose of the tractor protection valve? 

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

How does ABS improve braking performance?

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

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

When should you drain the air tanks?

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

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

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

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

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

Alcohol evaporates may be used to:

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

The trailer hand valve is used to:

A spring brake control valve is normally:

Brake fade can result:

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

The brake system on most large commercial vehicle use:

What should you observe when testing the emergency brake system?

An air tank drain valve that fails to function:

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

Air compressors:

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

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

What action should be taken if brake fade is detected?

A trailer supply valve is usually:

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

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

Why is it essential to inspect brake drums regularly?

Which factor can lead to brake fade?

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

What is the role of the tractor protection valve?

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

How often should drivers inspect slack adjusters?

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

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

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

Anti-lock braking systems (ABS):

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

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

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

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

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

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

At what point does the air compressor governor cut in?

How does a parking brake control valve operate?

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

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

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

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

Trailer couplers or 'glad hands' are usually:

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

What happens when moisture accumulates in the air brake system?

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

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

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

What happens if the air compressor fails during operation?

Spring brake chambers:

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

A properly functioning air brake system:

The normal operating pressure range for air brake system is:

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

How can drivers test the tractor protection system?

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

Which system ensures braking ability even if one circuit fails?

A vehicle's brakes must do more work when:

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

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

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

A governor controls air compressor

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

What does an air brake application pressure gauge indicate?

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

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

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

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

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

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

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

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

What is the purpose of the air compressor governor?

Wedge brake components include:

What is the purpose of brake linings in drum brakes? 

What might indicate a damaged brake chamber diaphragm?

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

Air brake chamber pushrod stroke is the result of:

What component helps control brake shoe movement in drum brakes?

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

Why is it important to monitor air tank pressure gauges?

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

What is the function of the modulator valve in ABS?

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

Disk brake components includes:

How often should air tanks be drained in humid conditions?

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

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

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

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

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

The brake pedal in air brake system is used to:

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

How should drivers test the low-pressure warning system?

How can drivers recognize a failing air compressor?

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

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

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

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