Combination Vehicles Practice Test | Oklahoma 2025 #2

Train for FREE online with our Oklahoma CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a OK combination license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

1 . Older trailers are not equipped with spring brakes. This means that if the air supply for a vehicle's air braking system leaks away:

The trailer will stop normally.

The trailer will not have brakes.

The trailer will speed up.

Older trailers do not have spring brakes. This means that if the air supply in an older trailer's air tank has leaked away, there will be no working brakes connected to the trailer and its wheels will turn freely.

2 . If a load is placed on one side of a trailer, the trailer:

May lean during turns.

May add extra support during turns.

May be easier to steer during turns.

Positioning the weight of a load on one side of a trailer may cause the trailer to lean to that side, increasing the risk of a rollover during turns and lane changes.

3 . Fully-loaded rigs:

Usually are very responsive to steering.

Are more likely to roll over than empty rigs.

Can stop quickly.

Fully-loaded rigs are more vulnerable to rolling over than empty rigs because the weight of the cargo gives the vehicles higher centers of gravity.

4 . During a trip, landing gear should be:

Completely raised.

Completely lowered.

Skimming the pavement.

Landing gear, or trailer supports, should always be completely raised before a vehicle is driven. Landing gear that is not entirely raised could catch on railroad tracks or other hazards on the roadway.

5 . What does an Anti-Lock Braking System (ABS) do?

It allows a vehicle's wheels to lock up.

It prevents a vehicle's wheels from locking up.

It makes turning a vehicle easier.

An Anti-Lock Braking System (ABS) helps prevent wheel lockup during hard braking. If ABS detects impending lockup, it reduces braking pressure to a safe level.

6 . When driving while pulling trailers, you should:

Make sudden turns with the steering wheel.

Avoid making sudden moves.

Push the accelerator to the floor when starting from a stop.

You should always steer gently and smoothly while pulling a trailer. Making sudden steering moves could cause the trailer to tip over.

7 . If the emergency air line loses pressure:

The service brakes will activate.

The tractor protection valve will close.

The rear trailer will detach from the combination.

The tractor protection valve keeps air in the trailer's braking system should the trailer break away or develop a leak. A loss of air pressure in the emergency line will cause the tractor protection valve to open and the emergency trailer brakes to activate.

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2025 Oklahoma | Frequently Asked Questions

To acquire a CDL Tank endorsement in Oklahoma, you first need a Commercial Driver's License (CDL). Then, study the state's CDL manual section on Tank Vehicles. After studying, you'll take a written knowledge test at a Department of Public Safety testing facility. Passing this test grants you the Tank endorsement on your CDL.

To obtain a CDL Tank license, you must first have a Commercial Driver's License (CDL). It's essential to study the Tank Vehicles section in the state's CDL manual. You'll then need to pass a written knowledge test at a Department of Public Safety testing facility. On passing, you'll receive the Tank endorsement on your CDL.

Specific training or experience isn't mandatory for a CDL Tank endorsement in Oklahoma. However, you need to study the Tank Vehicles section in the state's CDL manual. After that, pass a written knowledge test at a Department of Public Safety testing facility. It's also beneficial to have practical experience driving commercial vehicles.

Yes, to obtain a CDL Tank endorsement in Oklahoma, you must pass an additional written knowledge test focused on tank vehicles. This test covers topics like inspecting tank vehicles, driving tank vehicles, and safe driving rules. The information for the test can be found in the Oklahoma CDL manual's Tank Vehicles section.

The written test for a CDL Tank endorsement in Oklahoma covers various topics including: how to inspect tank vehicles, recognizing high center of gravity and its effects, handling bulk tanks, and understanding the dangers of surge. It also includes rules for safe driving, loading and unloading, and emergency procedures. The Oklahoma CDL manual provides further details.

The CDL Tank endorsement assessment in Oklahoma focuses on knowledge rather than specific driving maneuvers. It evaluates your understanding of inspecting tank vehicles, handling surge, recognizing the high center of gravity, safe driving practices, and emergency procedures. However, you must still demonstrate proficient general driving skills during your CDL road test.

Drivers with a CDL Tank endorsement must adhere to strict safety regulations due to the hazardous nature of the materials often transported. These include limitations on speed, specific loading/unloading procedures, and mandatory rest periods to prevent fatigue. Violations can result in fines, license suspension, or even revocation of the CDL endorsement.

No, liquid or gas materials cannot be transported without a valid CDL Tank endorsement in Oklahoma. This endorsement is required for drivers operating a commercial vehicle that is designed to transport any liquid or gaseous materials within a tank. Driving without the necessary endorsements can result in significant fines and penalties.

To add the CDL Tank endorsement to your current license in Oklahoma, you will need to complete the Tanker Vehicle Endorsement Application and pay the required fee. You may also need to pass a knowledge test specific to tank vehicles. If you meet the requirements, you can add the endorsement to your existing license without having to submit a fresh application.

Yes, handling hazardous materials with a CDL Tank endorsement in Oklahoma requires adherence to specific regulations. Drivers must pass the Hazmat Endorsement Knowledge Test and a TSA background check. They also need to follow safety protocols while loading, unloading, and transporting hazardous materials. Non-compliance can lead to penalties, including loss of endorsement.