COMBINATION TEST - TEXAS CDL
QUESTIONS AND CORRECT
ANSWERS
For the coupling to be complete, the safety catch for the fifth wheel locking lever must be:
✅✅CORRECT ANSW-over the locking gear.
What is the air leakage rate for a combination vehicle with the engine and brakes off?
✅✅CORRECT ANSW-Less than 3 PSI per minute.
What is the maximum air leakage rate for a combination vehicle with the engine off and the brakes
on? ✅✅CORRECT ANSW-4 PSI per minute.
A driver crosses the air lines when hooking up to an old trailer. What will happen? ✅✅CORRECT
ANSW-If the trailer has no spring brakes, he or she could drive away but wouldn't have trailer
brakes.
To unlock the fifth wheel, pull the release handle to the: ✅✅CORRECT ANSW-open position.
When driving a set of doubles, it is necessary to close the: ✅✅CORRECT ANSW-back shut-off valve
in the last trailer.
You are coupling a semitrailer to your tractor but have not yet backed under. The trailer is at the
right height when: ✅✅CORRECT ANSW-it will be raised slightly when the tractor is backed under
it.
.
In coupling, just before the tractor is coupled with the trailer you should: ✅✅CORRECT ANSW-
connect the emergency and service air lines.
In coupling, you should not move the tractor after it is coupled until you push in the air supply knob
and: ✅✅CORRECT ANSW-wait until the air pressure is normal.
What happens immediately if the service air line comes apart while driving, but the emergency line
is okay? ✅✅CORRECT ANSW-Nothing is likely to happen until you press the brakes.
QUESTIONS AND CORRECT
ANSWERS
For the coupling to be complete, the safety catch for the fifth wheel locking lever must be:
✅✅CORRECT ANSW-over the locking gear.
What is the air leakage rate for a combination vehicle with the engine and brakes off?
✅✅CORRECT ANSW-Less than 3 PSI per minute.
What is the maximum air leakage rate for a combination vehicle with the engine off and the brakes
on? ✅✅CORRECT ANSW-4 PSI per minute.
A driver crosses the air lines when hooking up to an old trailer. What will happen? ✅✅CORRECT
ANSW-If the trailer has no spring brakes, he or she could drive away but wouldn't have trailer
brakes.
To unlock the fifth wheel, pull the release handle to the: ✅✅CORRECT ANSW-open position.
When driving a set of doubles, it is necessary to close the: ✅✅CORRECT ANSW-back shut-off valve
in the last trailer.
You are coupling a semitrailer to your tractor but have not yet backed under. The trailer is at the
right height when: ✅✅CORRECT ANSW-it will be raised slightly when the tractor is backed under
it.
.
In coupling, just before the tractor is coupled with the trailer you should: ✅✅CORRECT ANSW-
connect the emergency and service air lines.
In coupling, you should not move the tractor after it is coupled until you push in the air supply knob
and: ✅✅CORRECT ANSW-wait until the air pressure is normal.
What happens immediately if the service air line comes apart while driving, but the emergency line
is okay? ✅✅CORRECT ANSW-Nothing is likely to happen until you press the brakes.
