CDL EXAM NEWEST ACTUAL QUESTIONS AND
ANSWERS (A+ GUIDE SOLUTION)
What two things are important to prevent rollover? - ANSWER ✔ - Keep cargo as close to the ground as possible
and drive slowly around turns
When you turn suddenly while pulling doubles, which trailer is most likely to turn over? - ANSWER ✔ - A rig pulling
triples (~27ft each)
Why should you not use the trailer hand brake to straighten out a jack knifing trailer? - ANSWER ✔ - The brake on
the trailer wheels caused the skid in the first place
What is off tracking? - ANSWER ✔ - the rear wheels follow a different path than the front wheels
When you back a trailer, how should you position your vehicle? - ANSWER ✔ - So you can back in a curved path
to the driver's side.
What types of trailers get stuck on railroad highway crossings? - ANSWER ✔ - Low slung units and single axle
tractors pulling a long trailer with its landing gear set to accommodate a tandem-axle trailer
Why should you not use the trailer hand valve while driving? - ANSWER ✔ - Because of the danger of making the
trailer skid.
Describe what the trailer air supply control does. - ANSWER ✔ - push it in to supply the trailer with air, pull it out
to shut the air off and put on the emergency brakes
Describe what the service line is for - ANSWER ✔ - carries air, which is controlled by the foot brake or hand valve
What is the emergency line for? - ANSWER ✔ - It supplies air to the trailer tanks and controls the emergency
brakes on combination vehicles
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, Why should you use chocks when parking a trailer without spring brakes? - ANSWER ✔ - to keep it from rolling if
the air leaks out and the emergency brake lets go
Where are shut-off valves? - ANSWER ✔ - service and supply air lines at the back of trailers
What might happen if the trailer is too high when you try to couple? - ANSWER ✔ - it may not couple correctly
After coupling, how much space should be between the upper and lower fifth wheel? - ANSWER ✔ - none
Should you look into the back of the fifth wheel to see if it is locked onto the kingpin? - ANSWER ✔ - Yes
To drive, do you need to raise the landing gear only until it just lifts off the pavement? - ANSWER ✔ - No, raise the
landing gear all the way up.
How do you know if your trailer is equipped with antilock brakes? - ANSWER ✔ - Check to see if it was
manufactured after 1998; trailers will have yellow malfunction lamps on the left side (front or rear); ECU or wheel
speed sensor wires coming from back of brakes
What is the proper coupling procedure? - ANSWER ✔ - 1. Inspect fifth wheel
2. Inspect area and chock wheels
3. Position tractor
4. Back up slowly
5. Secure tractor
6. Check trailer height
7. Connect air lines to trailer
8. Supply air to trailer
9. Lock trailer brakes
10. Back under trailer
11. Check connection for safety
12. Secure vehicle
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CDL
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ANSWERS (A+ GUIDE SOLUTION)
What two things are important to prevent rollover? - ANSWER ✔ - Keep cargo as close to the ground as possible
and drive slowly around turns
When you turn suddenly while pulling doubles, which trailer is most likely to turn over? - ANSWER ✔ - A rig pulling
triples (~27ft each)
Why should you not use the trailer hand brake to straighten out a jack knifing trailer? - ANSWER ✔ - The brake on
the trailer wheels caused the skid in the first place
What is off tracking? - ANSWER ✔ - the rear wheels follow a different path than the front wheels
When you back a trailer, how should you position your vehicle? - ANSWER ✔ - So you can back in a curved path
to the driver's side.
What types of trailers get stuck on railroad highway crossings? - ANSWER ✔ - Low slung units and single axle
tractors pulling a long trailer with its landing gear set to accommodate a tandem-axle trailer
Why should you not use the trailer hand valve while driving? - ANSWER ✔ - Because of the danger of making the
trailer skid.
Describe what the trailer air supply control does. - ANSWER ✔ - push it in to supply the trailer with air, pull it out
to shut the air off and put on the emergency brakes
Describe what the service line is for - ANSWER ✔ - carries air, which is controlled by the foot brake or hand valve
What is the emergency line for? - ANSWER ✔ - It supplies air to the trailer tanks and controls the emergency
brakes on combination vehicles
Page 1 of 9
CDL
©™
, Why should you use chocks when parking a trailer without spring brakes? - ANSWER ✔ - to keep it from rolling if
the air leaks out and the emergency brake lets go
Where are shut-off valves? - ANSWER ✔ - service and supply air lines at the back of trailers
What might happen if the trailer is too high when you try to couple? - ANSWER ✔ - it may not couple correctly
After coupling, how much space should be between the upper and lower fifth wheel? - ANSWER ✔ - none
Should you look into the back of the fifth wheel to see if it is locked onto the kingpin? - ANSWER ✔ - Yes
To drive, do you need to raise the landing gear only until it just lifts off the pavement? - ANSWER ✔ - No, raise the
landing gear all the way up.
How do you know if your trailer is equipped with antilock brakes? - ANSWER ✔ - Check to see if it was
manufactured after 1998; trailers will have yellow malfunction lamps on the left side (front or rear); ECU or wheel
speed sensor wires coming from back of brakes
What is the proper coupling procedure? - ANSWER ✔ - 1. Inspect fifth wheel
2. Inspect area and chock wheels
3. Position tractor
4. Back up slowly
5. Secure tractor
6. Check trailer height
7. Connect air lines to trailer
8. Supply air to trailer
9. Lock trailer brakes
10. Back under trailer
11. Check connection for safety
12. Secure vehicle
Page 2 of 9
CDL
©™
