Texas CDL Combination Practice Test (TX) 2

4.9 out of 5 (155 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Preparing for your Commercial Driver's License (CDL) in Texas is a crucial step toward a successful trucking career. Our Texas CDL combination practice test is designed to help you excel in your endorsement test. This particular practice permit test is the second in our series and focuses on real-world scenarios you'll encounter on the road. With 20 multiple-choice questions covering critical topics like inspection procedures, safe driving practices, air brake systems, and more, you'll get a comprehensive understanding of what it takes to drive safely and efficiently. You'll need to score at least 16 correct answers to pass, but don't worry-this Texas permit test practice is designed to be a no-pressure environment. You can take your time to learn and understand each question without the stress of the actual CDL combination test. We understand the unique driving conditions across Texas, from the bustling highways of Dallas to the open plains of West Texas and the humid conditions near the Gulf Coast. Our practice permit test incorporates scenarios that reflect these diverse conditions, ensuring you're prepared for anything. One of the critical areas covered is the risk of jackknifing, where the trailer swings out of alignment with the tractor. Learning to avoid this dangerous situation through smooth braking and careful handling is vital for safe driving. The varied questions on this Texas DMV combination practice test will boost your confidence and ensure you are well-prepared for the endorsement test. At the end of this Texas permit practice test, you'll receive a detailed summary of your performance. This summary highlights the questions you answered incorrectly and provides the correct answers for each, helping you learn from your mistakes. Unlike many paid CDL combination practice tests, ours is completely free. Despite being free, it offers just as many features and study opportunities as any expensive counterpart. Whether you're navigating the busy interstates around Houston or the rural roads stretching across the Texas Panhandle, this CDL combination test will equip you with the knowledge and skills needed to drive safely and effectively. Take advantage of this valuable resource to enhance your CDL preparation and get ready to hit the road with confidence in 2026!
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Sample Texas Combination Test Questions

Question 1

Why must the fifth-wheel plate be lubricated as required?

  1. A To prevent steering problems caused by excessive friction
  2. B To reduce wear on the tractor’s steer tires
  3. C To increase the vehicle’s fuel economy
  4. D To make the kingpin enter above the locking jaws

Correct answer: A – To prevent steering problems caused by excessive friction

The fifth-wheel plate provides the surface where the tractor and semitrailer move against each other while turning. Without proper lubrication, excessive friction can develop between those surfaces. The handbook warns that failing to keep the fifth-wheel plate greased as required can cause steering problems.

Source: Texas Commercial Motor Vehicle Drivers Handbook — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 2

Combination-vehicle air lines are often color-coded. Which pairing is commonly used?

  1. A Emergency line—black; service line—yellow
  2. B Emergency line—blue; service line—red
  3. C Emergency line—red; service line—blue
  4. D Emergency line—green; service line—white

Correct answer: C – Emergency line—red; service line—blue

The emergency or supply line is commonly identified in red, while blue is used for the service line. The Texas handbook describes these colors as aids for preventing crossed connections; it does not state that every system must use color coding. Some lines instead have metal tags marked “service” and “emergency.”

Source: Texas Commercial Motor Vehicle Drivers Handbook — §§ 6.2.4–6.2.5, “Trailer Air-lines” and “Hose Couplers (Glad Hands)”

Question 3

How should you verify that air reaches the rear of the last trailer?

  1. A Open each rear shut-off valve in turn and listen for escaping air
  2. B Open both air-line valves at the rear of the tractor only
  3. C Accelerate and make a hard service-brake application
  4. D Turn off the engine and check only for leaks near the tractor

Correct answer: A – Open each rear shut-off valve in turn and listen for escaping air

Secure the vehicle, build normal air pressure, and charge the trailer lines. At the rear of the last trailer, open and close the emergency-line shut-off valve, then do the same with the service-line valve while service pressure is applied. Escaping air confirms flow through each line. If air is absent, check whether the intermediate shut-off valves are open.

Source: Texas Commercial Motor Vehicle Drivers Handbook — § 6.5.2, “Combination Vehicle Brake Check”

Question 4

Which maintenance condition helps prevent friction-related steering difficulty between a tractor and semitrailer?

  1. A Keeping the landing gear lightly lowered while driving
  2. B Coating the electrical connector with fifth-wheel grease
  3. C Keeping the fifth-wheel plate properly lubricated
  4. D Operating with a dry kingpin and fifth-wheel surface

Correct answer: C – Keeping the fifth-wheel plate properly lubricated

The fifth-wheel plate must be greased as required. Lubrication permits the tractor and semitrailer to pivot without excessive friction during turns. A dry or inadequately lubricated fifth-wheel plate can create enough resistance to cause steering problems, so its condition should be checked before coupling.

Source: Texas Commercial Motor Vehicle Drivers Handbook — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 5

Which two practices most directly reduce the risk of a combination-vehicle rollover?

  1. A Place the load toward the front and maintain highway speed in turns
  2. B Keep the cargo low and drive slowly around turns
  3. C Place the load toward the rear and follow the posted maximum speed
  4. D Place the load toward the rear and brake while turning

Correct answer: B – Keep the cargo low and drive slowly around turns

Keeping cargo close to the ground lowers the vehicle’s center of gravity, while reducing speed limits the forces acting on the vehicle in a turn. The Texas handbook identifies these as two key rollover-prevention practices. Cargo should also be centered and distributed as evenly as possible rather than concentrated on one side.

Source: Texas Commercial Motor Vehicle Drivers Handbook — § 6.1.1, “Rollover Risks”

Question 6

What visual check confirms that the fifth-wheel jaws have locked around the kingpin correctly?

  1. A Look into the back of the fifth wheel
  2. B Accelerate sharply while watching the trailer
  3. C Turn the tractor sharply in both directions
  4. D Check only the trailer position in the mirrors

Correct answer: A – Look into the back of the fifth wheel

Use a flashlight if necessary and look into the back of the fifth wheel. Verify that the jaws are closed around the shank of the kingpin rather than its head. The coupling inspection should also confirm that there is no gap between the upper and lower fifth wheel and that the locking lever and safety latch are secured.

Source: Texas Commercial Motor Vehicle Drivers Handbook — § 6.4.1, “Coupling Tractor-Semitrailers”

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