Combination Test - Texas CDL Questions and Verified Correct
Answers
1. In coupling, just before the tractor is
coupled with the trailer you should: connect the emergency and
service air lines.
2. In coupling, you should not move the tractor af- wait until the air pressure is
normal.
ter it is coupled until you push in the air supply
knob and:
3. What happens immediately if the service Nothing is likely to happen
air line comes apart while driving, but the
emer- gency line is okay? until you press the brakes.
4. In coupling, before you back under the
trailer, how do you lock the trailer brakes? Pull out the yellow air supply
5. For the coupling to be complete, the safety knob.
catch for the fifth wheel locking lever must
be:
over the locking gear.
6. What is the air leakage rate for a
combination vehicle with the engine and
brakes off?
Less than 3 PSI per minute.
7. What is the maximum air leakage rate
for a combination vehicle with the engine
off and the brakes on? 4 PSI per minute.
8. A driver crosses the air lines when hooking
up to an old trailer. What will happen?
If the trailer has no spring
9. To unlock the fifth wheel, pull the release brakes, he or she could drive
han- dle to the:
away but wouldn't have trailer
brakes.
open position.
10. When driving a set of doubles, it is necessary to back shut-ott valve in the last
trailer.
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, Combination Test - Texas CDL Questions and Verified Correct
Answers
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Answers
1. In coupling, just before the tractor is
coupled with the trailer you should: connect the emergency and
service air lines.
2. In coupling, you should not move the tractor af- wait until the air pressure is
normal.
ter it is coupled until you push in the air supply
knob and:
3. What happens immediately if the service Nothing is likely to happen
air line comes apart while driving, but the
emer- gency line is okay? until you press the brakes.
4. In coupling, before you back under the
trailer, how do you lock the trailer brakes? Pull out the yellow air supply
5. For the coupling to be complete, the safety knob.
catch for the fifth wheel locking lever must
be:
over the locking gear.
6. What is the air leakage rate for a
combination vehicle with the engine and
brakes off?
Less than 3 PSI per minute.
7. What is the maximum air leakage rate
for a combination vehicle with the engine
off and the brakes on? 4 PSI per minute.
8. A driver crosses the air lines when hooking
up to an old trailer. What will happen?
If the trailer has no spring
9. To unlock the fifth wheel, pull the release brakes, he or she could drive
han- dle to the:
away but wouldn't have trailer
brakes.
open position.
10. When driving a set of doubles, it is necessary to back shut-ott valve in the last
trailer.
1/
7
, Combination Test - Texas CDL Questions and Verified Correct
Answers
close the:
2/
7
