問題一覧
1
The hand value should be used ?
to test the trailer brakes
2
When you get ready to back under a trailer, you should line up ?
directly in front of the trailer
3
You have pushed in the trailer air supply value. You should not move the vehicle until the whole system is ?
at normal pressure
4
To stop a trailer skid you should?
release the service brakes
5
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
6
Air brakes equipped trailers made before 1975
often do not have spring brakes
7
Air lines are often colored. The emergency lines is ? The service lines is?
red, blue
8
After connecting the air lines but before backing under the trailer, you should ?
supply air to the trailer, then pull out the trailer air supply value
9
The trailer air supply value should automatically close when air pressure falls to what range?
20-45 psi
10
Two things you can do to prevent rolling over are keep the cargo as low to the ground as possible:
go slow around turns
11
Air and electric lines from the tractor to the trailer should be ?
secured properly with enough slack for turns
12
The tractor protection value will close and the trailer emergency brakes will come on when there is a major leak in what airline?
emergency
13
Off tracking or cheating causes which of these to follow the widest path while making a turn?
3 axel tractor towing a 45 foot trailer
14
When you are uncoupling a loaded trailer, you should lower the landing gear until it ?
makes firm contact with the ground, than turn it a few extra cranks in low gear
15
If your vehicle gets stuck on a rail road crossing ?
get out the vehicle and away from the tracks
16
Why should you connect the air lines to a dummy coupler when they aren’t in use ?
it will keep dirt and water out of the lines
17
After you supply air to the trailer, make sure the brakes lines are not crossed and the brakes are working. This is done by?
applying and releasing the trailers brakes and listening for sounds
18
If you cross the air lines while coupling to an old trailer what will happen?
if the trailer had no spring brakes, you could drive away but you would not have trailer brakes
19
When checking that the trailer is securely coupled to the tractor, the landing gear should be ?
slightly raised
20
When should you use the hand value to park a combination vehicle?
never
21
When uncoupling a trailer, after you locked the trailer brakes, you should ?
back up gently to ease pressure on the 5th wheel jaws
22
Why should you be sure that the 5th wheel is greased as required?
to prevent steering problems
23
A trailer is most likely to jack knife when it is ?
empty
24
The 5th wheel locking is not locked after the jaws close around the kingpin. This means ?
the coupling is not right and should be fixed before driving
25
You have coupled to a trailer. Where should the landing gear be before driving away?
fully raised with the crank handle secure in the bracket
26
The air leakage rate for a combination vehicle with the engine off and the brakes off should be less than ? Per minute.
3 psi
27
The higher your center of gravity of your truck, the?
easier it is to turn over
28
You supply air to the trailer tanks by?
pushing in the trailer air supply vaule
29
When driving a set of double trailers, it is necessary to close shut off values on some trailers. Where are these values located?
at the back of trailer used to tow other trailers
30
When should you get out of your vehicle when you are backing a trailer?
when you are unsure of your part of travel
31
You will know the trailer you are using has ABS by ?
a yellow malfunction lamp on the left side
32
Your emergency line breaks or gets pulled apart while driving. The loss of pressure will cause the ?
emergency trailer brakes to come on
33
The best way to tell your trailer has started to skid is to ?
see it in you mirrors
34
Loss of air pressure in the emergency lines cause ?
the trailers emergency brake to come on
35
After you have coupled to a trailer, the tractor protection vault should be placed in the ? Position
normal
36
When backing a tractor under a trailer you should ?
always use the lowest reverse gear
37
When do you need to use chicks to park a trailer that does not have spring brakes?
always
38
The front trailer support are up and the trailer is resting on the tractor make sure ?
there is enough clearance between the fram and the landing gear
39
If you cannot make a right turn without swinging into another lane, you should?
turn wide as you complete the turn
40
A tractor with a ? trailer requires the shortest amount of stopping distance.
fully loaded
41
How should you test the trailer connection for security?
pull gently forward with the trailer brakes locked, then look at it carefully
42
The air leakage rate for a combination vehicle with the engine off and the brakes on should be less than ? Per minute
4 psi
43
To unlock the 5th wheel, you pull the handle to what position?
open
44
After you have coupled the trailer, you should begin raising the landing gear using what gear?
low gear
45
Which of these statements Is true ?
bobtails tractors can take longer to stop than fully loaded combination vehicles
46
What part of the kingpin should the jaws be locked around?
the shank
47
If you must back your trailer on a curved path,you should position your vehicle so you can back ?
to the drivers side
48
You have a major leak in the service line and you put on brakes. Service air pressure will escape and if it goes low enough will cause the ?
trailer emergency brakes to come on
49
After you lock the kingpin into the 5th wheel, you check the connection by ?
pulling the tractor ahead gently with trailer brakes locked
50
If your ABA is not working in your trailer, you should ?
driver normally, but get the system serviced soon
51
How much space should be between the upper and lower 5th wheel after coupling?
none
52
To be safe while driving you should leave at least 1 second for every ? Feet of vehicle length as following distance.
10 ft
53
Compared to straight truck or bus, there are ? things to inspect on a combination vehicle.
more
54
If the service line comes apart but the emergency line stays together, what will happen right away?
nothing is likely to happen until you try to apply the brakes
55
What gear should the transmission be in after you have uncoupled and are inspecting the trailer supports?
neutral
56
Before you back under a trailer, make sure of what?
the trailer brakes are locked