CDL Prep Air Brakes

The application pressure gauge shows how much air pressure you:

The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ______ psi.

3

Some air brake systems have an alcohol evaporator. What may happen if you don't keep the unit filled with alcohol?

4

Your truck or bus has a dual air brake system. If a low-pressure warning comes on for only one system, what should you do?

5

Why should you drain water from compressed air tanks?

6

The safety valve is set automatically when pressure is:

7

Your truck has a dual air system and one of the systems loses its pressure. What will happen?

8

Parking emergency brakes of trucks and buses can be legally held on by _____ pressure.

9

If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:

10

If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure build up from 85 to 100 PSI within _______ seconds

11

How should you check your service brakes are working properly?

12

A straight truck or bus air brake system should not leak at the rate of more than _____ psi per minute with the engine off and the brakes released.

13

During normal driving, spring brakes are usually held back by:

14

The air compressor stops pumping air at what psi?

15

The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below _____ psi.

16

The most common type of foundation brake found on heavy vehicles is the:

17

If you must make an emergency stop, you should brake so you:

18

If your vehicle has an alcohol evaporator every day during cold weather you should

19

The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more than:

20

The braking power of the spring brakes:

21

The air brake lag distance at 55 mph on dry pavement adds about ____ feet.

22

Total stopping distance for air brakes is longer than that for hydraulic brakes due to ______ distance.

23

It is accepted that too much heat caused by using your brakes too often can also cause:

24

Repeatedly partially increasing and pressing the brake pedal may result in:

25

The brake system that applies and releases the brakes when the driver uses the brake pedal is the ______ brake system.

26

A slack adjusters free play needs to be adjusted if it is more than about ______ when you pull hard on it?

27

The brake pedal in an air brake system:

28

The S-cam:

29

Under normal conditions, in order to engage the parking brakes the driver should:

30

All air brake equipped vehicles have:

31

With air brake vehicles, the parking brakes should be used

32

If the air compressor should develop a leak, what keeps the air in the tanks?

33

Which of these is NOT a proper time to apply the parking brakes?

34

To check the free play of manual slack adjusters of S-cam brakes, you should park on:

35

If the spring brakes are on when should you push the brake pedal

36

Excessive heat caused by using your brakes too often can also cause:

37

The use of brakes on a long and steep downgrade under normal conditions is only a supplement to:

38

The most important thing to do when a low air pressure warning comes on is:

39

The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:

40

Air braking takes more time than hydraulic braking because:

41

When brakes are applied, the brake shoes will press against the:

42

The safety valve discharges automatically at the pressure of:

43

Emergency stab breaking is:

44

If air pressure is not built up within the correct amount of time, then:

45

The safety valve reduces pressure at ____ psi.

46

What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?

47

The supply pressure gauge shows how much pressure:

48

It is not safe to drive a vehicle that has brake drums with cracks that are longer than ____ of the width of the friction area.

49

Your brakes are fading when:

50

If your vehicle has an alcohol evaporator, it is there to:

51

The air compressor governor controls:

52

Modern air brakes combine three different systems. They are the service, the parking, and the ____ brakes.

53

If you do not have automatic tank drains, how often should you drain the oil and water from the bottom of compressed air storage tanks?

54

The proper use of the brakes when going down a long steep grade after selecting a proper gear is to brake until your speed is about ____ below the posted speed and release your brake.