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Colorado CDL DMV Combination 2

Take 6 practice tests for CDL is the best way to prepare for your Colorado DMV exam is by taking our free practice tests. The following question are from real Colorado DMV practice test. More than 95% people pass a DMV exam when practice at DMV Practice Test.

Number of Test
6
Number of Question
20
Passing score
16
13%
  • 0Correct
  • 0Incorrect
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Ouch! While you were on a roll there for a few questions, you didn’t pass this time. But I know this test, and I think you’ll pass next time. Really.

1. Using the trailer hand brake while experiencing a trailer jackknife will:
Stop the skid.
Straighten the trailer.
Increase traction.
Continue the skid.

If you are experiencing a trailer jackknife, you can help your tires regain traction by releasing the brakes. Using a trailer hand brake while experiencing a skid will only cause the skid to continue.

2. If unsure if a trailer is equipped with ABS, you can:
Check under the trailer for wheel speed sensors coming from the back of the brakes.
Try driving on a slippery surface and see if ABS kicks in.
Assume it does have ABS.
Remove a tire and look for the ABS sensor on the axle.

Trailers and converter dollies built on or after March 1, 1998 are required to have Anti-Lock Braking Systems (ABS). This will be indicated by the presence of a yellow malfunction lamp. You can determine if older trailers have ABS by checking under the trailers for ECU and wheel speed sensor wires coming from the back of the brakes.

3. To lower the risk of a rollover, you should:
Load the cargo as far forward as possible.
Load the cargo as far back as possible.
Load the cargo as low as possible.
Stack the cargo as high as possible.

To lower the risk of a rollover, load your cargo as closely to the ground as possible. To further reduce this risk, take curves and corners slowly.

4. The emergency air line:
Is controlled by the foot brake.
Is connected to the relay valves.
Supplies air to the trailer air tanks.
Prevents skids.

The emergency air line (also known as the supply line) has two functions. The first is to supply air to the trailer air tanks on a combination vehicle, and the second is to control the emergency brakes.

5. Starting in which year were newly manufactured trailers required to have ABS?
1972
1987
1998
2004

All trailers and converter dollies manufactured on or after March 1, 1998 must be equipped with Anti-Lock Braking Systems (ABS).

6. To test the trailer service brakes, you should:
Move the vehicle forward slowly and apply the brakes with the brake pedal.
Reverse the vehicle slowly and apply the brakes with the hand control.
Reverse the vehicle slowly and apply the brakes with the brake pedal.
Move the vehicle forward slowly and apply the brakes with the hand control.

To test the trailer service brakes, you should first ensure that the braking system has a normal air pressure level, then release the parking brake. You should then move the vehicle forward slowly and apply the brakes with the hand control. If the trailer service brakes are working properly, you will feel the brakes activate.

7. While inspecting a coupling, you should go under the trailer and:
Detach the jaws from around the kingpin.
Make sure the locking lever is in the "emergency" position.
Remove the safety latch.
Look into the back of the fifth wheel.

While inspecting a coupling, you should go under the trailer and look into the back of the fifth wheel. Ensure that the fifth wheel jaws are secured around the shank of the kingpin.

8. A tractor protection valve is:
A device that keeps air in the tractor or truck brake system, should the trailer break away or develop a bad leak.
A device that prevents theft.
A device that controls fuel levels.
A device that allows the battery to recharge efficiently.

On combination vehicles with air brakes, the tractor protection valve keeps air in the tractor or truck brake system, should the trailer develop a bad leak or break away from the tractor.

9. After connecting the air lines to the trailer while coupling, you should:
Supply air to the trailer.
Chock the wheels.
Inspect the fifth wheel.
Connect the electrical cord.

Correctly following the steps to couple and uncouple trailers is vital to safely operating a combination vehicle. After connecting the air lines to the trailer while coupling, you should supply air to the trailer.

10. The easiest way to recognize that your trailer has begun to skid is to:
Ask another driver.
Use your mirrors to determine if the trailer has left the lane.
Release the brake pedal and then push it down again.
Watch the jackknife warning light on the control panel.

The easiest way to spot a trailer skid is to use your mirrors. Any time you brake hard, check your mirrors to ensure that your trailer is still in its proper position.

11. If a trailer's spring brakes do not release when you push the tractor air supply control, you should:
Check the air line connections.
Release the pintle hook.
Replace the spring brakes.
Drive normally without checking anything.

It is important that all of your vehicle's equipment is in proper working condition before you begin a trip. If a trailer's spring brakes do not release when you push in the tractor air supply control, you should make sure the air line connections are properly attached and sealed.

12. The best way to recognize that your trailer has begun to skid is by:
Seeing other drivers' faces.
Seeing it in your mirrors.
Feeling it.
Listening to the radio.

The earliest and best way to recognize the beginnings of a trailer skid is by seeing the trailer veer off-course in your mirrors.

13. Trailers with low underneath clearance may be difficult to drive:
On interstate highways.
Over railroad crossings.
On dirt roads.
At the posted speed limit.

Railroad-highway crossings may be difficult to cross when pulling a trailer with a low underneath clearance. In particular, both low-slung units and single-axle tractors pulling long trailers are especially challenging to drive over raised crossings.

14. What is another name for the service line?
Control line
Exchange line
Surplus line
Parallel line

The service line, also called the control line or signal line, carries air to the trailer brakes and is controlled by the foot brake or trailer hand brake.

15. One way to prevent a rollover is to:
Move cargo to the left side of the rig.
Keep cargo centered on the rig.
Move cargo to the right side of the rig.
Keep cargo as far from the ground as possible.

A rollover is more likely if cargo is unevenly loaded in a rig. To help prevent a dangerous rollover, it is important to keep a load as centered on the rig as possible.

16. Rollovers happen when:
A truck driver is driving too fast.
The driver of a vehicle in front of a truck is moving to slowly.
A truck driver is driving too slowly.
ABS is working effectively.

Rollovers happen when a vehicle is driven too fast. To reduce the risk of rollover, make sure the weight of cargo is loaded low to the ground, and that you take turns and curves slowly.

17. To prevent a rollover, a driver should:
Keep cargo low.
Place cargo high.
Keep cargo loose.
Turn quickly.

Rollovers can happen when a combination vehicle is turned too quickly. To help prevent the risk of rollover, it is important to keep the vehicle's center of gravity low by loading cargo as close to the ground as possible.

18. When a combination vehicle goes around a corner:
The turn should be made as tightly as possible.
The front and rear wheels move in different paths.
The rear wheels should run over the curb.
It is acceptable for street signs to be knocked over if they are too close to the road.

When a vehicle goes around a corner, the rear wheels follow a different path than the front wheels. This is called off-tracking. This effect is especially pronounced on vehicles with trailers.

19. Test the tractor protection valve by:
Removing the air supply knob.
Removing the parking brake control knob.
Releasing air with the brake pedal.
Releasing air with the gas pedal.

You should test the tractor protection valve by allowing the air supply to properly charge, turning off the engine, then releasing air from the system by pressing the brake pedal several times. The tractor protection valve should move into its emergency position when psi drops to an unsafe level.

20. Rollovers are most likely to happen when:
Drivers turn too fast.
Driver turn too slowly.
It is windy.
It is raining.

Rollovers happen when an operator turns too fast. Drivers should be sure to slow down before entering turns and curves, especially when transporting a fully-loaded rig.

Your Progress
  • 0Incorrect (4 allowed to pass)
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