CDL knowledge test

Question 1

You must park on ta side of a level, straight, four-lane divided highway. Where should you place the reflective triangles?

1 One within 10 feet of the rear of the vehicle, one about 100 feet to the rear, and one about 200 feet to the rear.

2 one within 10 feet of the rear of the vehicle, one about 100 feet to the rear, and one about 200 feet to the rear.

3 one within 10 feet of the front of the vehicle, one about 100 feet to the rear, and one about 200 feet to the rear.

Answer 1

1 One within 10 feet of the rear of the vehicle, one about 100 feet to the rear, and one about 200 feet to the rear.

Question 2

Which of these statements about overhead clearance is true?

1 The weight of the vehicle changes the height.

2 If the road surface causes your vehicle to tilt toward objects at the edge of the road, you should drive close to the shoulder

3 You should assume posted clearance signs are correct.

Answer 2

1 The weight of the vehicle changes the height.

Question 3

The driver’s manual suggests several things to do when you pass a vehicle. Which of these is NOT one of them?

1 Assume that another driver does not see you.

2 Lightly tap your horn.

3 At night, turn on your high beams before you start to pass and leave them on until you have completely passed the vehicle.

Answer 3

3 At night, turn on your high beams before you start to pass and leave them on until you have completely passed the vehicle.

Question 4

You are starting your vehicle in motion from a stop. As you apply power to the drive wheels, they start to spin. You should:

1 Try a lower gear.

2 Take your foot off the accelerator and apply the brakes.

3 Take your foot off the accelerator.

Answer 4

3 Take your foot off the accelerator.

Question 5

Which of these is the most important thing to remember about emergency braking?

1 Never do it without downshifting first.

2 Disconnecting the steering axle brakes will keep your vehicle in a straight-line during emergency braking.

3 If the wheels are skidding, you cannot control your vehicle.

Answer 5

3 If the wheels are skidding, you cannot control your vehicle.

Question 6

You can see a marking on a vehicle ahead of you. The marking is a red triangle with an orange center. What does the marking mean?

1 It is being driving by a student driver.

2 It may be a slow-moving vehicle.

3 The vehicle is hauling hazardous materials.

Answer 6

2 It may be a slow-moving vehicle.

Question 7

Which of these statements about backing a heavy vehicle is true?

1 Helpers should be out of the rivers sight and use only voice signals to communicate with the driver.

2 It is safer to back toward the right side of the than toward the driver’s side.

3 You should avoid backing whenever you can.

Answer 7

3 You should avoid backing whenever you can.

Question 8

The safety valve is set automatically when pressure is:

1 50
2 150
3 100

Answer 8

2 150

Question 9

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

1 Brake drums will not be fully pressurized.
2 Either the front of back brake will not be fully operational.
3 The manual slack adjusters of the S-cam brakes will not be set properly.

Answer 9

2 Either the front of back brake will not be fully operational.

Question 10

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

Air
Spring
Fluid

Answer 10

Spring

Question 11

If your truck has a properly funcitoning dual air brake system and minimum-sized air tanks, the air pressure should build up from 85 to 100 psi within how many seconds?

60
30
45

Answer 11

45

Question 12

The air compressor stops pumping air at what pst?

150
125
100

Answer 12

125

Question 13

The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks falls below _______psi

80
60
40

Answer 13

60

Question 14

Excessive use of the service brakes results in overheating, which can lead to:

Expansions of the brake drums.
Increase contact between the brake drums and linings
Proper adjustment of the S-cam.

Answer 14

Expansions of the brake drums.

Question 15

The braking power of the spring brakes:

Depends on the service brakes being in adjustment.
Increases when the service brakes are hot.
Is not affected by the condition of the service brakes.

Answer 15

Depends on the service brakes being in adjustment.

Question 16

An air brake system is fully charged at what psi?

100
125
75

Answer 16

125

Question 17

When brakes are applied, the brake shoes will press against the:
S-cam
Brake drum or disc
Slack adjuster

Answer 17

Brake drum or disc

Question 18

Your brakes are fading when:

You have to push harder on the brake pedal to control your speed on a downgrade.
Less pressure is needed on the brake pedal for each stop.
The brake pedal feels spongy when you apply pressure.

Answer 18

You have to push harder on the brake pedal to control your speed on a downgrade.

Question 19

The air compressor governor controls:
The speed of the air compressor.
When air is pumped into the air tanks.
Air pressure applied to the brakes.

Answer 19

When air is pumped into the air tanks.

Question 20

In ideal conditions, a truck or bus with air brakes going at 55mph would require the stopping distance of how many feet?

Less than 100’.
From 100-300’.
More than 300’.

Answer 20

More than 300’.

Question 21

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

Release the spring emergency/parking brakes to move a short distance.
Balance the service brake system when you are parked.
Stay parked twice as long without using up service air pressure.

Answer 21

Release the spring emergency/parking brakes to move a short distance.

Question 22

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

1
3
2

Answer 22

2

Question 23

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

spring pressure
air pressure
bolts or clamps

Answer 23

air pressure

Question 24

The air compressor stops pumping air at what psi?

150
125
100

Answer 24

125

Question 25

The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more than 2 psi in 45 seconds 3 psi in one minute 1 psi in 30 seconds

Answer 25

3 psi in one minute

Question 26

The braking power of the spring brakes: is not affected by the condition of the service brakes. increases when the service brakes are hot depends on the service brakes being in adjustment

Answer 26

depends on the service brakes being in adjustment

Question 27

An air brake system is fully charged at what psi? 100 125 75

Answer 27

125

Question 28

The S-cam Controls the air flow to each of the brake chambers Forces the brake shoes against the inside of the brake drum. Pulls the brake shoes away from the drum and allows the wheels to roll freely

Answer 28

Forces the brake shoes against the inside of the brake drum.

Question 29

The air compressor governor controls: Air pressure applied to the brakes When air is pumped into the air tanks. the speed of the air compressor

Answer 29

When air is pumped into the air tanks.

Question 30

The stop light switch: Tells you when you need to use your emergency brakes. Turns on the brake lights when you put on the air brakes. Tells you when the air brake system is low on air pressure.

Answer 30

Turns on the brake lights when you put on the air brakes.

Question 31

If you cannot complete your turn without entering another traffic lane, you should: Not make a turn and move to another place where you can make a turn without crossing other lane. Turn wide as you complete the turn. Turn wide before you start the turn.

Answer 31

Turn wide as you complete the turn.

Question 32

If the service line comes apart while you are driving a combination vehicle, but the emergency line stays together, what will happen right away? The trailers tank will exhaust through the open line. The emergency trailer brakes will come on. Nothing is likely to happen until you try to apply the brakes.

Answer 32

Nothing is likely to happen until you try to apply the brakes.

Question 33

After connecting the air lines but before backing under the trailer, you should: Walk around the rig to be sure that it is clear. Supply air to the trailer system, then pull out the air supply knob. Make sure that the trailer brakes are off.

Answer 33

Supply air to the trailer system, then pull out the air supply knob.

Question 34

You supply air the trailer tanks by: Pushing in the trailer air supply valve. Connecting the service line glad hands. Pulling out the trailer air supply valve.

Answer 34

Pushing in the trailer air supply valve.

Question 35

Why should you lock the tractor's glad hand to each other (or dummy couplers) when you are not towing a trailer? The connected brake circuit becomes a backup air tank. It will keep dirt or water out of the lines. If you did not, you could never build system pressure.

Answer 35

It will keep dirt or water out of the lines.

Question 36

After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in what position? Up position Down position Normal position

Answer 36

Normal position

Question 37

Off tracking or cheating causes which of these to follow the wider path while making a turn? Tractor towing a 45-feet trailer. Tractor with two 27-feet trailers. 53-foot bobtail.

Answer 37

Tractor with two 27-feet trailers.

Question 38

The air leakage rate for a combination vehicle (engines off, brakes on) should not be more than _____ psi per minute 4 3 2

Answer 38

4

Question 39

You have a major leak in the service line, and you put on the brakes. Service air will escape and cause the: Trailer emergency brakes to come on. Tractor spring brakes to lock up. Trailer tank pressure to be lost.

Answer 39

Trailer emergency brakes to come on.

Question 40

The safety latch for the fifth wheel locking lever must be ___ for a coupling to be complete. Under the locking lever Over the locking lever Straight up

Answer 40

Over the locking lever

Question 41

What gear should the tractor engine be in after you uncouple the trailer and are inspecting the trailer supports? Neutral Low reverse High reverse.

Answer 41

Neutral

Question 42

When uncoupling the trailer, after you shut off the trailer air supply and lock the trailer brakes, you should: Lower the trailer landing gear Put on your tractor parking brakes. Back up gently to ease pressure on the fifth wheel.

Answer 42

Back up gently to ease pressure on the fifth wheel.

Question 43

You are driving a combination vehicle when the trailer brakes away, pulling apart both air lines. You expect the trailer brakes to come on and: The tractor to lose air pressure. The trailer supply valve to stay open. The tractor protection valve to close.

Answer 43

The tractor protection valve to close.

Question 44

If you cannot complete your turn without entering another traffic lane, you should: Turn wide before you start the turn. Turn wide as you complete the turn. Not make a turn and move to another place where you can make a turn without crossing another lane.

Answer 44

Turn wide as you complete the turn.

Question 45

The hand valve should be used: As a parking brake To test the trailer brakes only with a foot brake

Answer 45

To test the trailer brakes

Question 46

After connecting the air lines but before backing under the trailer, you should: Supply air to the trailer system, then pull out the air supply knob. Make sure that the trailer brakes are off. Walk around the rig to make sure it is clear.

Answer 46

Supply air to the trailer system, then pull out the air supply knob.

Question 47

You supply air to the trailer tanks by: Connecting the service line glad hands. Pulling the trailer air supply valve. Pushing in the trailer air supply valve.

Answer 47

Pushing in the trailer air supply valve.

Question 48

You have a major leak in the service line, and you put on the brakes. Service air will escape and cause the: Tractor spring brakes to lock up. Trailer emergency brakes to come on. Trailer tank pressure to be lost.

Answer 48

Trailer emergency brakes to come on.

Question 49

The safety latch for the fifth wheel locking lever must be____ for a coupling to be complete Over the locking lever Under the locking lever Straight up

Answer 49

Over the locking lever

Question 50

When uncoupling the trailer, after you shut off the trailer air supply and lock the trailer brakes, you should: Lower trailer landing gear Back up gently to ease pressure on the fifth wheel. Put on your tractor brakes.

Answer 50

Back up gently to ease pressure on the fifth wheel.

Question 51

If you need to leave the road in a traffic emergency (such as a tire failure) you should? Try to get all wheels off the pavement Avoid braking until your speed has dropped to about 20mph Avoid a shoulder because most shoulders will not support a large vehicle.

Answer 51

Avoid braking until your speed has dropped to about 20mph

Question 52

You are driving an older truck with a manual transmission. What gear will you probably have to use to take a long, steep downhill grade? The same gear you would use to climb the hill A lower gear than you would use to climb the hill A high gear than you would use to climb the hill

Answer 52

The same gear you would use to climb the hill

Question 53

You are starting your vehicle in motion from a stop. As you apply power to the drive wheel they start to spin. You should? Take your foot off the accelerator. Take your foot off accelerator and apply the brakes. Try a lower gear.

Answer 53

Take your foot off the accelerator.

Question 54

Which of these statements about double-clutching is true? you can use the tachometer to tell you when to shift. Double clutching should not be used when the road is slippery Double clutching should be used with a heavy load

Answer 54

you can use the tachometer to tell you when to shift.

Question 55

You must stop on a hill with a two lane, two-way road. How far should you place your reflective triangles? As far back as necessary so others can see you. Within 200ft behind you Within 500ft behind you.

Answer 55

As far back as necessary so others can see you.

Question 56

Which of these is true about notifying the authorities after an accident occurs? An exact location is not necessary, just identify the road and vehicles involved. you should notify authorities about an accident before doing anything else. If you have a cell phone or CB radio you should notify the authorities before exiting the vehicle.

Answer 56

If you have a cell phone or CB radio you should notify the authorities before exiting the vehicle.

Question 57

Which of these is not a danger when the automatic transmission is forced into a low gear at high speeds? A loss of engine braking Damage to the transmission Loss of steering control

Answer 57

Loss of steering control

Question 58

When driving in cold weather your tire tread should: Provide enough contact to steer and push the vehicle through snow Be double the tread depth as normal weather Be checked every 100 miles or every 2 hours.

Answer 58

Provide enough contact to steer and push the vehicle through snow

Question 59

Which of these statements is NOT recommended for a left-hand turn? Start on the inside lane and swing right as you turn Use a right-hand lane if there are 2 turns lanes Start turning at the center of intersection

Answer 59

Start on the inside lane and swing right as you turn

Question 60

You are driving in a poorly lit area. If you cannot see well with your headlights, which of the following actions may help? Find another route that is well lit even if out of your way. Turn on your interior lights and adjust instrument lights. Use high beams when legal and keep interior lighting off.

Answer 60

Use high beams when legal and keep interior lighting off.

Question 61

A vehicle suddenly cuts in front of you, creating a hazardous situation. Which of the following should you NOT do? Honk your horn and stay close behind the vehicle. Signal and change lanes to avoid the hazard. Slow down to prevent a crash.

Answer 61

Honk your horn and stay close behind the vehicle.

Question 62

When driving on a snow-packed road, you should reduce your speed by? 1/2 1/3 1/4

Answer 62

1/2

Question 63

The bridge formula Permits less maximum axle weight for the axles that are close together Permits less maximum axle weight for axles spaced apart. Permits the same maximum axle weight for any axle.

Answer 63

Permits less maximum axle weight for the axles that are close together

Question 64

When should you test your parking brakes? While moving at a very slow speed. While the vehicle is parked. When backing.

Answer 64

While the vehicle is parked.

Question 65

Controlled braking is: Slamming on the brakes hard making the wheels lock up Applying the brakes firmly without locking them up Pressing brakes until the wheels lock up, releasing and then reapplying.

Answer 65

Applying the brakes firmly without locking them up

Question 66

If you do not have a CB radio what is the procedure you should do on the scene of an accident? Protect the area Notify authorities Care for the injured.

Answer 66

Protect the area

Question 67

You may get hung up on railroad tracks if: You cross double tracks too slowly The crossing has a steep approach You try to shift gears when crossing the track.

Answer 67

The crossing has a steep approach

Question 68

The safest way to make turns without entering another traffic lane is: Turn wide as you complete the turn. You should turn wide before you start turning. You should not make a turn and move to another place where you can make a turn without crossing into another lane.

Answer 68

Turn wide as you complete the turn.

Question 69

Compared to a straight truck or bus there are ______ things to inspect than a combination behicle Fewer Same amount More

Answer 69

Fewer

Question 70

You have a major leak in the service line brakes, and you put on the brakes. Service air will escape and cause the_____ Trailer emergency brakes to come on. Trailer tank pressure to be lost. Tractor spring brakes to lock up.

Answer 70

Trailer emergency brakes to come on.