Combination

Question 1

When backing a tractor under a trailer, you should:
a) Always use the lowest reverse gear
b) Always approach the trailer at a slight angle
c) Do it quickly to ensure that the kingpin is locked into the fifth wheel

Answer 1

a) Always use the lowest reverse gear

Question 2

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

Answer 2

c) Normal

Question 3

The fifth wheel locking lever is not locked after the jaws have closed around the kingpin. This means that:
a) The trailer will not swivel on the fifth wheel
b) The parking lock is off, and you may drive away
c) The coupling is not right and should be fixed before driving the coupled unit

Answer 3

c) The coupling is not right and should be fixed before driving the coupled unit

Question 4

Off tracking or cheating causes which of these to follow the wider pass while making a turn?
a) Tractor towing a 45 feet long trailer
b) Tractor with two 27 feet long trailers
c) 53 feet long bobtail

Answer 4

b) Tractor with two 27 feet long trailers

Question 5

The air lines on combination vehicles are often colored to prevent them from getting mixed up. The emergency line is____ and the service line is____:
a) Red, blue
b) Black, yellow
c) Blue, red

Answer 5

a) Red, blue

Question 6

Semi-trailers made before 1975 that are equipped with air brakes:
a) Usually need a glad hand converter
b) Often do not have spring brakes
c) Have only a service air line

Answer 6

b) Often do not have spring brakes

Question 7

The air leakage rate for a combination vehicle (engine off, brakes on) should be less than ____ psi per minute:
a) 2
b) 3
c) 4

Answer 7

c) 4

Question 8

Compared to a straight truck or bus there are ___ things to inspect on combination vehicles:
a) Fewer
b) The same amount
c) More

Answer 8

c) More

Question 9

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

Answer 9

a) Trailer emergency brakes to come on

Question 10

A tractor with a ____ trailer will require the shortest amount of stopping distance:
a) Empty
b) Lightly loaded
c) Fully loaded

Answer 10

c) Fully loaded

Question 11

When you get ready to back under a semitrailer, you should line up:
a) The kingpin to engage the driver’s side locking jaw first
b) Directly in front of the trailer
c) The left rear dual outer wheel with the kingpin

Answer 11

b) Directly in front of the trailer

Question 12

To unlock the fifth wheel, the locking lever should be placed in the ____ position:
a) Neutral
b) Closed
c) Open

Answer 12

c) Open

Question 13

The tractor protection valve will close, and the trailer emergency brakes will come on when there is a major leak in the ____ brake line:
a) Service
b)Parking
c)Emergency

Answer 13

c)Emergency

Question 14

When coupling, the proper position of the fifth wheel is:
a)Level with the ground
b)Tilted down toward the end of the trailer
c)Tilted up toward the end of the trailer

Answer 14

b)Tilted down toward the end of the trailer

Question 15

What gear should the tractor be in after you uncouple the trailer and are inspecting the trailer supports?
a) Neutral
b) Low reverse
c) High reverse

Answer 15

a) Neutral

Question 16

You have coupled to a semitrailer. Where should you put the iron trailer supports before driving away?
a) Raised half way with the crank handle secured in its bracket
b) Fully raised with the crank handle secured in its bracket
c) Three turns off the top with the crank handle secured in its bracket

Answer 16

b) Fully raised with the crank handle secured in its bracket

Question 17

The safety catch for the fifth wheel locking lever must be ____ for coupling to be complete:
a) Over the locking lever
b) Under the locking lever
c) Straight up

Answer 17

a) Over the locking lever

Question 18

After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. This is done by:
a) Lifting the brake pedal
b) Watching your mirrors to see if the trailer lights come on
c) Applying and releasing the trailer brakes and listening for the sound of the brakes

Answer 18

c) Applying and releasing the trailer brakes and listening for the sound of the brakes

Question 19

Before you back under a trailer, make sure that:
a)The trailer brakes are locked
b)The tractor protection valve is normal
c)The air supply knob is in

Answer 19

a)The trailer brakes are locked

Question 20

When you are coupling a loaded trailer, you should lower the landing gear until it:
a) Makes firm contact with the ground, then turn the crank handle a few extra turns
b) Makes firm contact with the ground and lifts the trailer off the fifth wheel
c) Reaches the ground

Answer 20

a) Makes firm contact with the ground, then turn the crank handle a few extra turns

Question 21

What will happen if the air lines are crossed when you hook up to an old trailer?
a) The hand valve will apply the tractor brakes instead of the trailer brakes
b) If the trailer has no spring brakes, you could drive away but you wouldn’t have trailer brakes
c) The brake lights will come on when the brake pedal is pressed

Answer 21

b) If the trailer has no spring brakes, you could drive away but you wouldn’t have trailer brakes

Question 22

There are two things a driver can do to prevent a rollover. They are (1) keep the cargo as close to the ground as possible and (2):
a) Make sure that the brakes are properly adjusted
b) Keep both hands firmly on the steering wheel
c) Go slow around turns

Answer 22

c) Go slow around turns

Question 23

To stop a trailer skid you should:
you are uncoupling a loaded trailer, you should lower the landing gear until it:
a) Use the trailer hand brake
b) Release the service brakes
c) Countersteer

Answer 23

b) Release the service brakes

Question 24

Why should you be sure the fifth wheel plate is greased as required?
a) To ensure a good electrical connection
b) To prevent steering problems
c) To reduce heat and noise

Answer 24

b) To prevent steering problems

Question 25

Your emergency air line breaks or gets pulled apart while driving. The loss of pressure will cause the: a) Air compressor to unload instead of pumping air b) Tractors air to dump into the trailer tank through the service line c) Emergency trailer brakes to come on

Answer 25

c) Emergency trailer brakes to come on

Question 26

When connecting the glad hands, press the two coupler rubber seals together at what angle to each other? a) 45 degrees b) 90 degrees c) 180 degrees

Answer 26

b) 90 degrees

Question 27

Which of these statements is true? a) The brakes and suspension system of combination vehicles work best with a light load b) Light vehicles need more braking power to stop than heavy ones c) Bobtail tractors can take longer to stop than a combination vehicle loaded to maximum gross weight

Answer 27

c) Bobtail tractors can take longer to stop than a combination vehicle loaded to maximum gross weight

Question 28

After you have coupled the trailer, you should start raising the landing gear by using: a) Low gear b) Intermediate c) High gear

Answer 28

a) Low gear

Question 29

You supply air to the trailer tanks by: a) Pushing in the trailer air supply valve b) Pulling out the trailer air supply valve c) Connecting the service line glad hands

Answer 29

a) Pushing in the trailer air supply valve

Question 30

Which part of the kingpin should the locking jaws close around? a) The shank b) The head c) The base

Answer 30

a) The shank

Question 31

How much space should be allowed between the upper and lower fifth wheel after coupling? a) 1⁄4 inch b) Just enough to sit on c) Nothing

Answer 31

c) Nothing

Question 32

You have pushed in the trailer air supply valve. You should not back a tractor under a trailer until the whole system is: a) Empty b) At normal pressure c) Between 60 and 80 psi

Answer 32

b) At normal pressure

Question 33

You are coupling a tractor to a semitrailer. You have connected the air lines. Before backing under the trailer, you should: a) Supply air to the system then pull out the air supply knob b) Pull ahead to test the glad hand connections c) Make sure that the trailer brakes are off

Answer 33

a) Supply air to the system then pull out the air supply knob

Question 34

The air brake leakage rate for a combination vehicle (engine off, brakes off) should be less than ___ psi per minute: a) 1 b) 2 c) 3

Answer 34

c) 3

Question 35

The safest way to make a turn without entering another traffic lane is to: a) You should turn wide before you start the turn b) You should turn wide as you complete the turn c) You should not make the turn and find another place where you can turn without crossing into another lane

Answer 35

b) You should turn wide as you complete the turn

Question 36

The higher the center of gravity of your truck, the a) Easier to turn around the corner b) More stable the truck is while turning c) Easier it is to turn over

Answer 36

c) Easier it is to turn over

Question 37

The hand valve should be used: a) Only with the foot brake b) To test the trailer brakes c) As a parking brake

Answer 37

b) To test the trailer brakes

Question 38

When driving a set of doubles, it is necessary to close which shut- off valves on the last trailer? a) Front b) Middle section c) Back

Question 39

There are two things a driver can do to prevent a rollover. They are (1) go slow and (2): a) Make sure that the brakes are properly adjusted b) Keep both hands firmly on the steering wheel c) Keep the cargo as close to the ground as possible

Answer 39

c) Keep the cargo as close to the ground as possible

Question 39

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

Answer 39

c) Nothing is likely to happen until you try to apply the brakes

Question 40

After connecting the air lines but before backing under the trailer you should: a) Supply air to the system then pull out the air supply knob b) Pull ahead to test the glad hand connections c) Make sure that the trailer brakes are off

Answer 40

a) Supply air to the system then pull out the air supply knob

Question 41

You are coupling a tractor to a semitrailer and have backed up but are not under it. What should you hook up before backing under? a) The emergency and service air lines b) The electrical service cable c) Nothing. Back up and lock the fifth wheel

Answer 41

a) The emergency and service air lines

Question 42

Why should you lock the tractor glad hands to each other or to a dummy coupler when you are not towing a trailer? a) The connected brake circuit becomes a back-up air tank b) It will keep dirt or water out of the lines c) If you don’t, you could never build system pressure

Answer 42

b) It will keep dirt or water out of the lines

Question 43

While driving behind another vehicle under good conditions you should allow at least one second between your vehicle and the vehicle ahead for each____ (how many) feet of your vehicle length? a) 10 b) 20 c) 30

Answer 43

a) 10

Question 44

Glad hands are usually connecting which of these: a) Electric lines from the tractor to the trailer b) Kingpin from the trailer to the locking jaws of the fifth wheel c) Service and emergency air lines from the vehicle to the trailer

Answer 44

c) Service and emergency air lines from the vehicle to the trailer

Question 45

You are about to back your tractor under a semitrailer. The trailer is at the right height when: a) The kingpin is about 11⁄4 inches above the fifth wheel b) End of the kingpin is even with the top of the fifth wheel c) Trailer will be lifted slightly when the tractor backs under it

Answer 45

c) Trailer will be lifted slightly when the tractor backs under it

Question 46

While checking if the trailer is securely coupled to the trailer, the landing gear should be: a) Fully raised b) Slightly raised c) Fully lowered

Answer 46

b) Slightly raised

Question 47

Air and electrical lines from the tractor to the trailer should be: a) Fully tight b) Secured, but with enough loop to turn c) Resting on the frame of the tractor

Answer 47

b) Secured, but with enough loop to turn

Question 48

After you lock the kingpin into the fifth wheel, you should check the connection by: a) Pulling forward 50 feet while turning right and left b) Backing up with the trailer brakes released c) Pulling the tractor forward gently with the trailer brakes locked

Answer 48

c) Pulling the tractor forward gently with the trailer brakes locked

Question 49

Where should the tractor be when you inspect the landing gear after uncoupling from the trailer? a) With the tractor frame under the trailer b) Completely cleared from the trailer c) With the fifth wheel directly beneath the kingpin

Answer 49

a) With the tractor frame under the trailer

Question 50

The front trailer supports are up, and the trailer is resting on the tractor. Make sure: a) There is enough clearance between the top of the tractor tires and the nose of the trailer b) There is enough clearance between the tractor frame and the landing gear c) Both a and b are correct

Answer 50

c) Both a and b are correct

Question 51

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

Answer 51

a) Back up gently to ease pressure on the fifth wheel

Question 52

Air brake equipped trailers made before 1975: a) Often do not have spring brakes b) Usually need a glad hand converter c) Cannot be legally operated on interstate highways

Answer 52

a) Often do not have spring brakes

Question 53

The iron trailer supports are up and the trailer is resting on the tractor, be sure that: a) There is enough clearance between upper and lower fifth wheels b) The safety latch is in the unlocked position c) There is enough clearance between the tractor frame and the landing gear

Answer 53

c) There is enough clearance between the tractor frame and the landing gear

Question 54

When checking the trailer emergency brakes the tractor protection control valve should be placed in what condition? a) Normal b) Emergency c) Neutral

Answer 54

b) Emergency

Question 55

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

Answer 55

c) The tractor protection valve to close

Question 56

In normal driving, some drivers use the land valve before the brake pedal to prevent a jackknife. Which of the statements is true? a) It should not be done b) It results in less skidding than using the brake pedal alone c) It is the best way to brake and keep the truck in a straight line

Answer 56

a) It should not be done

Question 57

When should you use the hand valve to park a combination vehicle? a) To park at loading docks b) To park on a grade c) Never

Answer 57

c) Never

Question 58

If the brakes are not released when you push the trailer air supply valve you should: a) Check the air line connection b) Cross the air lines c) Check the electrical cable

Answer 58

a) Check the air line connection

Question 59

How should you test the tractor-semitrailer connection for security? a) Look at it carefully b) Rock the trailer back and forth with the trailer brakes locked c) Pull gently forward in low gear against the locked trailer brakes then look at it carefully

Answer 59

c) Pull gently forward in low gear against the locked trailer brakes then look at it carefully