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TFH CDL study > General Knowledge > Flashcards

General Knowledge Flashcards

(107 cards)

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1
Q

The distance you should look ahead while driving is ________ of a mile at highway speed

A

12-15 seconds, 1/4, QRT

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2
Q

What is not the proper time to apply the parking brake?

A

If the brakes are hot

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3
Q

In air brake vehicles the parking brake should be used?

A

Anytime you are parked.

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4
Q

What is counter steering?

A

Turning the wheel back in the opposite direction after steering to avoid an emergency.

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5
Q

Snow packed road. Reduce speed by at least what?

A

1/2

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6
Q

What can brake fade be caused by?

A

Brakes getting hot

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7
Q

Airlines are often colored. The emergency line is? _____

The service line is?_____

A

emergency: RED
service: BLUE

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8
Q

If your ABS is not working on your trailer you should?

A

Drive normally but get the system serviced

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9
Q

What is the distance you should look ahead while driving at low speed?

A

1 block

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10
Q

If you must make an emergency stop you should brake so you…

A

Can keep vehicle in a straight line and turn if it is necessary

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11
Q

You should supply air to the trailer tanks by…

A

Pushing in the trailer air valve

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12
Q

For air brake systems in good condition the air compressor should start pumping at what PSI?

A

100

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13
Q

Total stopping distance for air brakes is longer than hydraulics because?

A

Brake lag

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14
Q

Your emergency line breaks if gets pulled apart while driving. The loss of pressure will cause the _______________.

A

emergency trailer brakes to come on

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15
Q

All air brake equipped vehicles must have what?

A

A supply pressure gauge.

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16
Q

What actions are NOT recommended for a Left turn?

A

When you start in the inside lane and you swing right as you turn.

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17
Q

Emergency Controlled Braking is…

A

When you apply the brakes as hard as you can w/o locking the brakes.

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18
Q

A slack adjuster probably needs adjustment if it moves more than _______ when you pull on it.

A

1 inch

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19
Q

What gear should the trans be in after you have uncoupled and are inspecting the trailer?

A

Neutral

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20
Q

The hand valve should be used…

A

To test the trailer brakes

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21
Q

You must park on the side of a level. Straight two lane road where should you place your triangles?

A

10 ft , 100 ft , 100 ft

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22
Q

You have pushed in the trailer air supply valve. You should not move the vehicle until the whole system is…

A

Normal pressure

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23
Q

The driver must be able to see a low air pressure that must come on before the pressure in the tanks falls below what? ________

A

60 psi

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24
Q

Air compressor should stop pumping at what PSI?

A

125 PSI

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25
How do you test the air service brakes?
Brake firmly while slowly moving forward.
26
If you cannot make a right turn w/o swinging into another lane you should?
Turn wide as you complete the turn
27
Before you back under a trailer make sure of what?
The trailer brakes are locked.
28
If your truck or bus has a dual parking control valve you can use the pressure from another tank to __________________.
Release the spring brakes to move the vehicle in an emergency.
29
Where should the tractor be when you inspect landing gear after uncoupling the trailer?
With the tractor frame under the trailer.
30
Safest way to make a turn when entering another traffic lane is…
When you turn side as you complete the turn.
31
The trailer air supply valve should automatically close when air pressure falls to what range?
20-45 PSI
32
You have coupled to a trailer. Where should the landing gear be before driven away?
Fully raised with the Crank Handle secure.
33
Retarders can be used when?
Only where permitted by law
34
When driving in cold weather your tire depth should?
Provide enough traction to steer and get through the snow.
35
What should you do if you see a hazard in the road way ahead of you?
Use your 4-way flashers or brakes lights to warn others.
36
What does emergency braking mean?
Responding to a hazard by slowing the vehicle.
37
Loss of air pressure in the emergency line __________
Causes the trailers emergency brakes to come on
38
If a straight truck goes into a front wheel skid it will?
Go straight ahead even if the wheels are turned.
39
Trailer is most likely to Jack Knife when it’s ______.
Empty
40
The tractor protection valve will close and the trailer emergency brakes will come on when there is a major leak in what airline?
Emergency
41
Which of these lights cannot be checked at the same times?
Turn signals, brake lights, 4-ways
42
The higher your center of gravity of your truck the _____________.
easier it is to turn over.
43
The modulating control valve allows you to control the ________.
Spring brakes
44
Most common type of foundation brake found in heavy vehicles is the?
S-Cam brake
45
Stab braking
* involves releasing the brakes only after the wheels lock up * Help to keep the vehicle from skidding
46
Off tracking or cheating causes which of these to follow the widest path while making a turn,
3 axle tractor towing a 45ft trailer.
47
After connecting the airlines but before backing under the trailer you should _____________.
Supply air to the trailer then pull out the trailer air supply valve.
48
After you have coupled to a trailer the tractor protection valve should be in the _______ position.
Normal
49
What activates the stop switch?
Air pressure
50
Where should you place warning devices if you must stop on a one-way divided highway?
10, 100 and 200 feet
51
How many tie downs should a cargo be held with?
Minimum of 2
52
Which of these are not a danger of rough acceleration? (A) Tire Damage (B) Mechanical Damage (C) Damage to Coupling
(A) Tire Damage
53
Backing a commercial vehicle is:
Always dangerous
54
After starting the engine coolant temp. should ______________.
Begin a gradual rise to the normal range
55
Whenever you double your speed, how much more distance does it take to stop?
4 times
56
What is the bridge formula?
Permit less maximum axle weight for axles that are closer together.
57
What statement is true about downshifting in a curve?
To downshift for a curve, you should do so before you enter the curve.
58
What 3 things add up to the total stopping distance?
(1) Perception Distance (2) Reaction Distance (3) Braking Distance
59
Perception distance is the distance your vehicle travels from the time…
The eyes see a hazard to the time the brain knows it’s a hazard
60
How far ahead of the vehicle should the driver look while driving?
12-15 seconds
61
To stop a trailer skid you should?
Release the service brakes
62
Air brake equipped trailer made before 1973 often do not have ___________.
Spring brakes
63
You are coupling a tractor to a semi-trailer and you have backed up but are not under it. What should you hook up before backing under it?
Emergency & Service airlines
64
If your brakes fail on a downgrade you must first:
Look outside your vehicle for another means of slowing it.
65
If you must have a heavy load that is slowing you down on an upgrade you should?
Shift in a lower gear
66
Emergency stab braking is where you…
Brake as hard as you can, release the brakes when the wheels lock and apply the brakes again
67
The total weight of powered unit trailer and cargo is called?
Gross Combination Weight
68
Which system should receive extra attention during cold weather?
Exhaust
69
Most serious skids result from?
Driving too fast for conditions.
70
Hydroplaning is more likely when?
Tire pressure is low.
71
What should you do when your vehicle hydroplanes?
Release the accelerator.
72
In the event of a rear tire failure, dual rear tire will usually prevent?
Fish tailing
73
How do you correct a rear wheel acceleration skid?
Stop acceleration
74
How much space should be between the Upper and Lower fifth wheel after coupling?
None.
75
To be safe while driving, you should leave at least 1 second for every ___ feet of vehicle length.
10
76
When using tie downs, what weight should the tie down be able to lift?
One and a half times the weight.
77
When should you use the hand valve to park a combo vehicle?
Never.
78
What part of the Kingpin should the Jaws be locked around?
Shank.
79
When hydraulic brakes fail while driving. What action do you take?
Pump the brake pedal to generate pressure.
80
If your truck has a dual air system and 1 system is low on air pressure then…
Either the Front or Rear brakes will not be operating fully.
81
What happens to tar on the road when pavement gets hot?
Bleeds. Making the road surface slippery.
82
Proper way to signal lane changes?
Signal early, Change lanes slowly & smoothly
83
After you have coupled the trailer you should begin raising the landing gear using what gear?
Low
84
You are coupling a tractor to a trailer. The trailer is at the right height when:
The trailer is raised slightly when the tractor is backed under it.
85
During normal driving spring brakes are usually held back by:
Air pressure
86
What is the average effective braking distance?
216 feet
87
How often should you check your mirrors?
Every 8-10 seconds
88
When checking that the trailer is securely coupled to the tractor, the landing gear should be:
Slightly raised
89
What is true about ABS?
It changes the way you brake in an emergency
90
Braking power of the spring brakes:
Depends on the brakes being in adjustment
91
If the spring brake is on, when should you push the brake pedal?
Never
92
Air brakes take more time to stop than hydraulic brakes because:
Air takes more time to flow through the lines than hydraulic fluid.
93
Air loss rate for straight truck w/ engine off and brakes on:
3 PSI in 1 min (60 seconds)
94
The safety valve is set automatically to reduce pressure in the tanks at what PSI?
150 PSI
95
If the service line comes apart but the emergency line stays together. What will happen right away?
Nothing is likely to happen until you apply the brakes.
96
Air leakage rate for combination
4 PSI
97
The application pressure gauge shows you how much pressure:
You are applying to the brakes
98
Supply pressure gauge shows how much pressure:
Is in the air tanks
99
The brake pedal in an air brake system:
Controls the air pressure applied to put on the brakes
100
Spring brakes on trucks will bring it to a stop automatically when it falls to what range?
20-45 PSI
101
Excessive heat caused by using your brakes too often can cause the:
Brakes to fail
102
If truck has ABS it will have a _______ malfunction.
Yellow
103
Modulating control valve allows you to operate the:
Spring brakes
104
How often should you drain the water from the air tanks?
End of the day
105
Modern air brakes combine 3 different systems
(1) Service (2) Parking (3) Emergency
106
Air brake lag at 55 mph adds how many feet of stopping distance?
32 feet
107
Cracks in the drum can not be longer than _____.
1/2 inch

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