combination vehicles test

Combination Vehicles TestQuestion #1 of 37

Glad hands are coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer.Top of Form

True

FalseBottom of FormQuestion #2 of 37Which of the following best describes what the trailer air supply control does.Top of Form

You pull it out to supply the trailer with air, and push it in to shut the air off and put on the trailer emergency brakes.

You push it in to supply the tractor with air, and pull it out to supply the trailer with air.

You push it in to supply the trailer with air, and pull it out to shut the air off and put on the trailer emergency brakes.

You push it in to supply the trailer with air, and pull it out to supply the tractor with air.Bottom of FormQuestion #3 of 37Which shut-off valves should be open and which closed?Top of Form

All shut-off valves should be closed.

All shut-off valves should be open.

The front trailers shut-off valves open and the rear closed.

The rear trailers shut-off valves open and the front closed.

Bottom of FormQuestion #4 of 37The trailer hand valve should be used only as a supplement to the engine braking effect.Top of Form

True

False

Bottom of FormQuestion #5 of 37Shut-off valves can be found at the front and back of each trailer.Top of Form

True

FalseBottom of FormQuestion #6 of 37What might happen if the trailer is too high when you try to couple?Top of Form

It may not couple correctly.

The king pin may fall off.

The trailer may tip and flip over.

All of the above.Bottom of FormQuestion #7 of 37When you turn suddenly while pulling double trailers, which trailer is most likely to turn over?Top of Form

The front trailer.

The rear trailer.

Both trailers.

Neither trailer is more likly to turn over.

None of the above.

Bottom of FormQuestion #8 of 37The trailer hand valve should be used only to test the trailer brakes.Top of Form

True

FalseBottom of FormQuestion #9 of 37Which air line carries air to the trailer air tanks.Top of Form

Service

EmergencyBottom of FormQuestion #10 of 37Charge the trailer air brake system and check that the trailer rolls freely. Then stop and pull out the trailer air supply control valve. Pull gently on the trailer with the tractor to check that the trailer emergency brakes are on.Top of Form

This is not a test.

This is how can you test the tractor protection valve.

This is how can you test the trailer emergency brakes.

This is how can you test that air flows to all trailers.

This is how can you test the trailer service brakes.

Bottom of FormQuestion #11 of 37Which air line carries air that is controlled by the trailer handbrake.Top of Form

Service

EmergencyBottom of FormQuestion #12 of 37What two things are most important to prevent a rollover?Top of Form

Evenly loaded trailer and properly inflated tires.

Keeping the cargo as close to the ground as possible and driving slowly around turns.

The weight and length of the vehicle.

Keeping the cargo center of gravity as high as possible and drive slowly around turns.

None of the above.Bottom of FormQuestion #13 of 37If the front trailer shut-off valves closed, and the rear trailer shut-off valves are open, you will hear air flowing out of the rear trailer shut-off valves.Top of Form

True

FalseBottom of FormQuestion #14 of 37

You push in the trailer air supply control to supply the trailer with air, and pull it out to shut the air off and put on the trailer emergency brakes.Top of Form

True

FalseBottom of FormQuestion #15 of 37Charge the trailer air brake system and push the air supply knob in. Shut the engine off. Step on and off the brake pedal several times to reduce the air pressure in the tanks. The trailer air supply control should pop out when the air pressure falls into the pressure range specified by the manufacturer.Top of Form





This is how you test the air pressure gauge.

None of the above.Bottom of FormQuestion #16 of 37You should look into the back of the fifth wheel to see if it is locked onto the kingpin.Top of Form

True

False

Bottom of FormQuestion #17 of 37After coupling, there should be no space or gap between the upper and lower fifth wheel.Top of Form

True

FalseBottom of FormQuestion #18 of 37Go to the rear of the rig. Open the emergency line shut-off valve at the rear of the last trailer. You should hear air escaping, showing the entire system is charged. Close the emergency line valve. Open the service line valve to check that service pressure goes through all the trailers (this test assumes that the trailer handbrake or the service brake pedal is on), then close the valve. If you do NOT hear air escaping from both lines, check that the shut-off valves on the trailer(s) and dolly(s) are in the OPEN position.Top of Form





This is not a test.Bottom of FormQuestion #19 of 37Check for normal air pressure, release the parking brakes, move the vehicle forward slowly, and apply trailer brake with the hand control trolley valve, if so equipped.Top of Form





This is not a test.

Bottom of FormQuestion #20 of 37To drive, you need to raise the landing gear only until it just lifts off the pavement.Top of Form

True

FalseBottom of FormQuestion #21 of 37Why should you never use the trailer hand valve while driving?Top of Form

It should not be used in driving because the trailer brakes will not be applied evenly.

It is ok to use it while driving on dry roads.

It should not be used in driving because it releases too much air from the system.

It should not be used in driving because of the danger of making the trailer skid.Bottom of FormQuestion #22 of 37After coupling, how much space should be between the upper and lower fifth wheel?Top of Form

1/32 inch.

1/16 inch.

1/8 inch.

1/4.

None of the above.

Bottom of FormQuestion #23 of 37

Describe what the service line is for.Top of Form

It carries air which is controlled by the foot brake or the trailer handbrake.

It carries air which is controlled by the foot brake.

It carries air which is controlled by the the trailer handbrake.

All of the above.

None of the above.Bottom of FormQuestion #24 of 37What is offtracking?Top of Form

Offtracking is when the front wheels follow a different path than the front wheels.

Offtracking is when the rear wheels go into a skid and the front wheels continue in a straight line.

Offtracking is when the front wheels go one direction and the trailer wheels go in the other direction.

Offtracking is when the rear wheels follow a different path than the front wheels.

None of the above.


What is the emergency air line for?Top of Form

It supplies air to the tractor air tanks and controls the service brakes on combination vehicles.

It supplies air to the trailer air tanks and controls the service brakes on combination vehicles.

It supplies air to the trailer air tanks and controls the emergency brakes on combination vehicles.

It supplies air to the tractor air tanks and controls the emergency brakes on combination vehicles.

None of the above.

Bottom of FormQuestion #26 of 37Combination vehicles and the rearward amplification each trailer has after a quick lane change is reffered to as what?Top of Form

Crack the road effect.

Crack the whip effect.

The trailer effect.

The new driver effect.

Bottom of FormQuestion #27 of 37Which air line carries air that is controlled by the foot brake.Top of Form

Service

EmergencyBottom of FormQuestion #28 of 37Large combination vehicles take longer to stop when they are fully loaded than when they are empty.Top of Form

True

FalseBottom of FormQuestion #29 of 37What is a bobtail?Top of Form

It is what connects the air line to the trailer.

It is the pin under the trailer that connects to the 5th wheel.

It is a tractor with no trailers connected to it.

It is another name for a dolly.


The emergency air line supplies air to the trailer air tanks and controls the service brakes on combination vehicles.Top of Form

True

False

Bottom of FormQuestion #31 of 37Large combination vehicles take longer to stop when they are empty than when they are fully loaded.Top of Form

True


Combination vehicles are usually heavier, longer, and require more driving skill than single commercial vehicles.Top of Form

True


Combination vehicles are usually lighter, shorter, and require less driving skill than single commercial vehicles.Top of Form

True

False

Bottom of FormQuestion #34 of 37Fully loaded rigs are ten times more likely to roll over in a crash than empty rigs.Top of Form

True


Why should you use tire chocks when parking a trailer without spring brakes?Top of Form

If the air supply in the service air tank has leaked away there will be no emergency brakes enabling the trailer wheels to turn freely.

If the air supply in the trailer air tank has leaked away there will be no emergency brakes enabling the trailer wheels to turn freely.

If the air supply in the trailer air tank has leaked away there will be no emergency brakes enabling the tractor wheels to turn freely.

If the air supply in the trailer air tank has leaked away there will be no service brakes enabling the trailer wheels to turn freely.Bottom of FormQuestion #36 of 37Why should you never use the trailer handbrake to straighten out a jackknifing trailer?Top of Form

The trailer wheels caused the skid in the first place. Once the trailer wheels grip the road again, the trailer will start to follow the tractor and straighten out.

The tractor wheels caused the skid in the first place. Once the trailer wheels grip the road again, the trailer will start to follow the tractor and straighten out.

The tractor wheels caused the skid in the first place. Once the trailer wheels grip the road again, the trailer will start to push the tractor and straighten out.

This is the only time that you should use the trailer brake.

None of the above.Bottom of FormQuestion #37 of 37Where are shut-off valves located?Top of Form

At the front of each trailer.

At the back of each trailer.

At the front and back of each trailer.

On the back of the tractor.Bottom of Form

Final Score: 0%95% of trucking companies that hire new truck drivers require a hazmat endorsement! Take the General Knowledge Test, Hazmat Test, Air Brake Test, Combination Vehicles Test.User Statistics

QuestionYour AnswerCorrect Answer% who Answered this Question Correctly

Combination vehicles are usually lighter, shorter, and require less driving skill than single commercial vehicles.

UnansweredFalse96%

What two things are most important to prevent a rollover?UnansweredKeeping the cargo as close to the ground as possible and driving slowly around turns.90%

Fully loaded rigs are ten times more likely to roll over in a crash than empty rigs.UnansweredTrue81%

What is the emergency air line for?

UnansweredIt supplies air to the trailer air tanks and controls the emergency brakes on combination vehicles.81%

Combination vehicles and the rearward amplification each trailer has after a quick lane change is reffered to as what?UnansweredCrack the whip effect.92%

What is offtracking?UnansweredOfftracking is when the rear wheels follow a different path than the front wheels.88%

Large combination vehicles take longer to stop when they are empty than when they are fully loaded.UnansweredTrue83%

Which shut-off valves should be open and which closed?UnansweredThe front trailers shut-off valves open and the rear closed.83%

What is a bobtail?UnansweredIt is a tractor with no trailers connected to it.89%

What might happen if the trailer is too high when you try to couple?UnansweredIt may not couple correctly.83%

The trailer hand valve should be used only to test the trailer brakes.UnansweredTrue87%

After coupling, how much space should be between the upper and lower fifth wheel?UnansweredNone of the above.88%

Glad hands are coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer.

UnansweredTrue97%

Check for normal air pressure, release the parking brakes, move the vehicle forward slowly, and apply trailer brake with the hand control trolley valve, if so equipped.UnansweredThis is how can you test the trailer service brakes.68%

When you turn suddenly while pulling double trailers, which trailer is most likely to turn over?UnansweredThe rear trailer.93%

Combination vehicles are usually heavier, longer, and require more driving skill than single commercial vehicles.

UnansweredTrue96%

To drive, you need to raise the landing gear only until it just lifts off the pavement.UnansweredFalse94%

The emergency air line supplies air to the trailer air tanks and controls the service brakes on combination vehicles.

UnansweredFalse72%

Which of the following best describes what the trailer air supply control does.UnansweredYou push it in to supply the trailer with air, and pull it out to shut the air off and put on the trailer emergency brakes.81%

Large combination vehicles take longer to stop when they are fully loaded than when they are empty.UnansweredFalse83%

Where are shut-off valves located?UnansweredAt the back of each trailer.79%

The trailer hand valve should be used only as a supplement to the engine braking effect.UnansweredFalse81%

Why should you never use the trailer hand valve while driving?UnansweredIt should not be used in driving because of the danger of making the trailer skid.93%

After coupling, there should be no space or gap between the upper and lower fifth wheel.UnansweredTrue94%

Describe what the service line is for.

UnansweredAll of the above.67%

You push in the trailer air supply control to supply the trailer with air, and pull it out to shut the air off and put on the trailer emergency brakes.

UnansweredTrue91%

Why should you never use the trailer handbrake to straighten out a jackknifing trailer?UnansweredThe trailer wheels caused the skid in the first place. Once the trailer wheels grip the road again, the trailer will start to follow the tractor and straighten out.78%

Shut-off valves can be found at the front and back of each trailer.UnansweredFalse77%

You should look into the back of the fifth wheel to see if it is locked onto the kingpin.UnansweredTrue95%

Which air line carries air that is controlled by the trailer handbrake.UnansweredService69%

Why should you use tire chocks when parking a trailer without spring brakes?

UnansweredIf the air supply in the trailer air tank has leaked away there will be no emergency brakes enabling the trailer wheels to turn freely.65%

Which air line carries air to the trailer air tanks.UnansweredEmergency67%

Go to the rear of the rig. Open the emergency line shut-off valve at the rear of the last trailer. You should hear air escaping, showing the entire system is charged. Close the emergency line valve. Open the service line valve to check that service pressure goes through all the trailers (this test assumes that the trailer handbrake or the service brake pedal is on), then close the valve. If you do NOT hear air escaping from both lines, check that the shut-off valves on the trailer(s) and dolly(s) are in the OPEN position.UnansweredThis is how can you test that air flows to all trailers.81%

Which air line carries air that is controlled by the foot brake.UnansweredService95%

Charge the trailer air brake system and check that the trailer rolls freely. Then stop and pull out the trailer air supply control valve. Pull gently on the trailer with the tractor to check that the trailer emergency brakes are on.UnansweredThis is how can you test the trailer emergency brakes.78%

If the front trailer shut-off valves closed, and the rear trailer shut-off valves are open, you will hear air flowing out of the rear trailer shut-off valves.UnansweredFalse79%

Charge the trailer air brake system and push the air supply knob in. Shut the engine off. Step on and off the brake pedal several times to reduce the air pressure in the tanks. The trailer air supply control should pop out when the air pressure falls into the pressure range specified by the manufacturer.UnansweredThis is how can you test the tractor protection valve.52%

Final Score: 0%95% of trucking companies that hire new truck drivers require a hazmat endorsement! Take the General Knowledge Test, Hazmat Test, Air Brake Test, Combination Vehicles Test.

combination vehicles test

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