Practice test

Air Brake Questions

Answer Air brake questions

Question 1 of 48
Question 1

When the brakes are applied on a moving vehicle, what happens to the vehicle’s kinetic energy?

Question 2

What is the primary purpose of brake fluid in a hydraulic brake system used on passenger vehicles?

Question 3

What do air brake systems use to apply the brakes on most large commercial vehicles?

Question 4

Which statement is true about air brake systems?

Question 5

Which statement about vehicles equipped with air brake systems is correct?

Question 6

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

Question 7

Why must compressed air be handled carefully in an air brake system?

Question 8

What is the primary function of an air compressor in an air brake system?

Question 9

How are air compressors commonly powered on vehicles equipped with air brake systems?

Question 10

How are air compressors typically mounted on vehicles with air brake systems?

Question 11

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

Question 12

What is the normal operating pressure range for a vehicle air brake system?

Question 13

Why is it unsafe to operate a vehicle when the air pressure is outside the air brake system’s normal operating range?

Question 14

What air tanks are commonly used on vehicles with air brake systems to store compressed air?

Question 15

Why must air tanks in an air brake system be drained regularly?

Question 16

What do air pressure gauges indicate in a vehicle equipped with a dual-service air brake system?

Question 17

What is the purpose of a safety valve in an air brake system?

Question 18

What is the purpose of audible and visual low air pressure warning devices in an air brake system?

Question 19

What is the primary function of an air dryer in an air brake system?

Question 20

What is the purpose of an alcohol evaporator in an air brake system?

Question 21

What is the primary function of the brake pedal in a vehicle with an air brake system?

Question 22

What is the function of a manually controlled front-wheel limiting valve in an air brake system?

Question 23

What causes the stroke of an air brake chamber pushrod?

Question 24

Which statement about air brake chambers is correct?

Question 25

How can spring brake chambers be distinguished from service brake chambers?

Question 26

Why must spring brake chambers be handled carefully during maintenance?

Question 27

Why are spring brake chambers mechanically compressed or caged?

Question 28

Which statement about the spring brake control valve is correct?

Question 29

When can the spring brake control valve be used?

Question 30

When do the spring brakes automatically apply on a vehicle with an air brake system?

Question 31

What components are included in a trailer brake subsystem?

Question 32

What is the purpose of trailer couplers (gladhands) in an air brake system?

Question 33

How can trailer couplers (gladhands) usually be identified and protected from incorrect connection?

Question 34

What is the result of crossed trailer couplers (gladhands)?

Question 35

What is the purpose of the trailer hand valve in an air brake system?

Question 36

How is the trailer supply valve typically identified in a vehicle with an air brake system?

Question 37

What is the primary function of a tractor protection valve on a towing vehicle?

Question 38

What is the function of a spring brake priority trailer brake subsystem?

Question 39

In a spring brake priority trailer brake system, what is the only way to apply the trailer brakes if trailer service air is lost?

Question 40

Which components are used in an ‘S’ cam brake system?

Question 41

Which components are used in a disc brake system?

Question 42

Which components are used in a wedge brake system?

Question 43

How does increasing a vehicle’s speed or weight affect the demand on its brakes?

Question 44

What can happen if a vehicle is overloaded?

Question 45

What is the effect of repeated or severe brake use?

Question 46

What can result from excessively high brake temperatures?

Question 47

What happens when a vehicle’s brakes are out of adjustment?

Question 48

What happens when a vehicle’s tires skid?