Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CDL EXAM > CDL Combination Test > Flashcards

CDL Combination Test Flashcards

1
Q

What will happen if the service air line comes apart while you are driving a combination vehicle?

A. The emergency trailer brakes will come on
B. the trailer’s air tank will exhaust through the open line
C. Nothing is likely to happen until you put on your brakes
D. Nothing at all is going to happen

A

C. Nothing is likely to happen until you put on your brakes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fully loaded rigs are ____ times more likely to rollover in a crash than empty rigs.

A. 5
B. 10
C. 20
D. 8

A

B. 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Failure to keep the _____ lubricated cold cause steering problems because of friction between tractor and trailer.

A. trailer protection valve
B. fifth wheel plate
C. glad hands
D. air supply knob

A

B. fifth wheel plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

If the service and emergency air lines are crossed when hooking up an old trailer, what will happen?

A. You will be able to drive away, but you won’t have trailer brakes
B. The trailer spring brake will release
C. Nothing will happen
D. Water and dirt will enter the air lines

A

A. You will be able to drive away, but you won’t have trailer brakes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When lowering the landing gear of a loaded trailer,

A. lower the gear until it makes firm contact with ground
B. turn the crank in low gear a few extra turns after the landing gear makes firm contact with the ground
C. lift the trailer off the fifth wheel
D. turn the crank in high gear a few extra turns after the landing gear makes firm contact with the ground

A

B. turn the crank in low gear a few extra turns after the landing gear makes firm contact with ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The standard following distance behind other vehicles is at least

A. two seconds for each ten feet of vehicle length
B. one second for each twenty feet of vehicle length
C. two seconds for each ten feet of vehicle length plus one second if going over 40 mph
D. one second for each ten foot vehicle length plus another second if going over 40 mph

A

D. one second for each ten foot vehicle length plus another second if going over 40 mph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

After the tractor has coupled with the semitrailers, in what position should you put the front trailer supports, or landing gear, before driving away?

A. Partway up without the crank handle secured
B. Halfway up
C. Fully raised with the crank handle safely secured
D. On the ground

A

C. Fully raised with the crank handle safely secured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The air package rate for a combination vehicle (engine off, brake off) should be less than ___ psi per minute

A. 1
B. 2
C. 3
D. 4

A

C. 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

You are coupling a tractor and semitrailer, and ready to back your trailer under a semi-trailer. When is the trailer at the right height?

A. When the tractor and semitrailer are even
B. When the kingpin is lower than the fifth wheel
C. When the trailer is raised slightly by the tractor as the tractor is backed under it
D. When the trailer is raised high above the trailer as the tractor is backed under it

A

C. When the trailer is raised slightly by the tractor as the tractor is backed under it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why should the trailer glad hands be locked together or attached to “dead end,” or dummy, couplers when not in use?

A. To keep dirt out of the lines
B. To keep air pressure normal
C. To prevent air from escaping
D. To keep the service and emergency glad hands from getting mixed up

A

A. To keep dirt out of the lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When coupling a tractor and semitrailer, you must lock the kingpin into the fifth wheel. Which is the best way to check the connection?

A. Drive forward
B. Lock the trailer brakes and pull the tractor gently forward
C. Lock the trailer brakes and pull the tractor quickly forward
D. Back up and unlock the trailer brake

A

B. Lock the trailer brakes and pull the tractor gently forward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When coupling with a semitrailer, back the tractor up

A. at an angle to the trailer
B. directly in front of the trailer
C. in front of the right wheel
D. slightly off the center of the trailer

A

B. directly in front of the trailer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When the wheels of a trailer lock up and the trailer begins to swing around ____ is likely to occur.

A. rollover
B. offtracking
C. trailer jackknife
D. a rear wheel braking skid

A

C. trailer jackknife

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When coupling a trailer to a semitrailer, what should you hook up before backing under the trailer?

A. The emergency and service air lines
B. Nothing; you are ready to back up
C. The trailer air supply control
D. The tractor protection valve

A

A. The emergency and service air lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When coupling, the fifth wheel jaws should close around the _______ of the kingpin.

A. head
B. bottom
C. middle
D. shank

A

D. shank

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following may happen if the tractor protection valve doesn’t work right?

A. An air hose or trailer brake lead could drain all the air from the trailer and possibly cause a loss of control in the vehicle.
B. The pressure may rise in the trailer
C. Nothing will happen
D. The engine may shut off

A

A. An air hose or trailer brake lead could drain all the air from the trailer and possibly cause a loss of control in the vehicle.

17
Q

The tractor protection valve will close automatically if air pressure is low or in the range of

A. 0-10 psi
B. 46 psi or above
C. 20-45 psi
D. 11-19 psi

A

C. 20-45 psi

18
Q

In combination vehicles, the trailer service brake should be tested with the ____, but controlled in normal operation with the ____.

A. hand valve; foot brake
B. trailer air supply control; hand valve
C. foot brake; hand valve
D. trailer emergency valve; foot brake

A

A. hand valve; foot brake

19
Q

When parking trailers without spring brakes, use ____ to safely secure the vehicle.

A. the emergency brake
B. the trailer hand brake
C. wheel chocks
D. the parking brake

A

C. wheel chocks

20
Q

The earliest and best way to recognize that your trailer has started to skid is by

A. seeing it in your mirrors
B. feeling the rig “pull” to the right or left
C. carefully watching how other drivers are reacting to your vehicle
D. periodically applying the brakes to check for traction

A

A. seeing it in your mirrors

21
Q

How much space should be between the upper and lower fifth wheel after coupling?

A. 6 inches
B. 1 foot
C. No space
D. More than 1 foot

A

C. No space

22
Q

Which of the following is a coupling device used to connect the service and emergency air lines from the truck or tractor to the trailer?

A. The tractor protection valve
B. The trailer air supply control
C. The relay valve
D. Glad hands

A

D. Glad hands

23
Q

Emergency lines on combination vehicles are often color coded to keep them from getting mixed up. The service lines are coded with the color ____, and the emergency lines are coded with the color ____.

A. blue…red
B. red…black
C. red…blue
D. blue…yellow

A

A. blue…red

24
Q

To supply air to the trailer air tanks in a combination vehicle, you must

A. pull out the trailer air supply control
B. press the trailer hand brake
C. open the relay valve
D. push in the trailer supply control

A

D. push in the trailer supply control

25
Q

What are the two purposes of the emergency air line on combination vehicles?

A. To supply air to the trailer air tanks and control the emergency brakes
B. To control the emergency brakes and carry air controlled by the foot brake
C. To carry air, which is controlled by the foot brake only
D. To supply air to the trailer air tanks and to connect the trailer air tank to the trailer air brakes

A

A. To supply air to the trailer air tanks and control the emergency brakes

26
Q

The “normal” position of the trailer air supply control is used for

A. shutting the air off
B. putting on the trailer emergency brake
C. pulling a trailer
D. parking a trailer

A

C. pulling a trailer

27
Q

When should the trailer hand valve be used?

A. To park the trailer
B. To drive the trailer
C. To test the trailer brake
D. Only in an emergency

A

C. To test the trailer brake

28
Q

Which of the following is the correct definition of offtracking?

A. When a vehicle is turning the corner, the front wheels and rear wheels follow the same path
B. When a vehicle is turning the corner, the front wheels lead the rear wheels around the turn
C. Keeping the front of the rig as close to the curb as possible to avoid entering other lanes
D. When a vehicle is turning the corner, the rear wheels follow a different path than the front wheels

A

D. When a vehicle is turning the corner, the rear wheels follow a different path than the front wheels

29
Q

Your trailer has begun to skid. You should

A. use the trailer hand brake to straighten out the rig
B. apply the foot brake hard, and come to a full stop
C. release the foot brake to get traction back
D. turn hard in the direction of the skid

A

C. release the foot brake to get traction back

30
Q

Which of the following reduces the risk of rollover?

A. Loading the cargo on one side of the truck only
B. Keeping the cargo as close to the ground as possible
C. Changing lanes quickly
D. None of the above

A

B. Keeping the cargo as close to the ground as possible

CDL EXAM (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions