Ohio CDL Combination Test (OH) 2026

4.8 out of 5 (102 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Get ready to ace your Commercial Driver's License (CDL) combination vehicles endorsement with our thorough Ohio DMV practice test. This test is designed to cover all the critical areas you'll need to master, such as coupling and uncoupling procedures, pre-trip inspections, driving techniques, backing and maneuvering, and the essential air brake systems. Each Ohio BMV practice test consists of 20 multiple-choice questions, and you'll need to get at least 16 correct to pass. This ensures that you have a solid understanding of the increased stopping distances required for combination vehicles due to their heavier weight, which is crucial for road safety. The combination CDL practice test provides a realistic simulation of the questions you'll face on the actual test. You'll encounter real-life driving scenarios that help you not only prepare for the written test but also become a safer driver overall. This practical approach ensures that you are well-equipped to handle the unique challenges of driving larger, heavier combination vehicles. One of the significant advantages of our Ohio CDL combination test is the flexibility it offers. Available online 24/7, you can take the Ohio permit practice test at your convenience, fitting your study sessions into your busy schedule without having to adhere to the fixed timings of a driving school. This means you can practice whenever it suits you best, whether that's early in the morning, late at night, or during a lunch break. Upon completing the CDL practice test, you'll have the opportunity to review your answers. This review process is invaluable, as it allows you to go over any hints and explanations for the questions you missed, reinforcing your knowledge and helping you understand the material more deeply. This targeted review helps ensure that you're fully prepared for the actual test and increases your chances of passing on the first try. Start your preparation with our comprehensive Ohio combination CDL test today and build the confidence you need to succeed. With our practice permit test, you're not just studying for an test; you're learning to become a more skilled and safer driver on the road.
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Sample Ohio Combination Test Questions

Question 1

When disconnecting a semitrailer, which methods are acceptable for protecting the air and electrical connections?

  1. A Hang the electrical plug with its open end facing down
  2. B Attach the glad hands to dummy couplers
  3. C Lock the glad hands together when the couplings permit it
  4. D All three methods are acceptable, as applicable

Correct answer: D – All three methods are acceptable, as applicable

The Ohio manual's uncoupling procedure permits attaching the glad hands to dummy couplers or locking them together when their design allows it. The electrical cable should be hung with the plug facing downward to keep moisture out. All lines and cables should also be supported where they will not be damaged while the tractor is driven.

Source: Ohio Commercial Driver License Manual (HSY 7605) — § 6.4.2, “Uncoupling Tractor-Semitrailers”

Question 2

What happens when the trailer air-supply control is operated?

  1. A It applies only the tractor's service brakes
  2. B It mechanically secures the trailer to the fifth wheel
  3. C It measures the pressure inside the trailer tanks
  4. D It supplies trailer air when pushed in and shuts off air and applies the emergency brakes when pulled out

Correct answer: D – It supplies trailer air when pushed in and shuts off air and applies the emergency brakes when pulled out

The trailer air-supply control operates the tractor protection valve. Pushing the control in supplies air to the trailer brake system. Pulling it out shuts off the trailer's air supply and applies the trailer emergency brakes.

Source: Ohio Commercial Driver License Manual (HSY 7605) — § 6.2.3, “Trailer Air Supply Control”

Question 3

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

  1. A To make every uncoupling procedure faster
  2. B To improve the trailer's electrical connection
  3. C To prevent friction from causing steering problems
  4. D To eliminate all heat and noise from the coupling

Correct answer: C – To prevent friction from causing steering problems

The fifth-wheel plate must be properly greased so the tractor and trailer can pivot without excessive friction. Inadequate lubrication can resist that movement and cause steering problems. Lubrication should be checked as part of the fifth-wheel inspection before coupling.

Source: Ohio Commercial Driver License Manual (HSY 7605) — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 4

Which combination has an increased risk of becoming hung up on a raised railroad-highway crossing?

  1. A A high-clearance tank vehicle
  2. B A tandem-axle tractor with correctly adjusted landing gear
  3. C A low-clearance trailer or a long trailer behind a single-axle tractor with landing gear set for a tandem-axle tractor
  4. D Any placarded trailer, regardless of its ground clearance

Correct answer: C – A low-clearance trailer or a long trailer behind a single-axle tractor with landing gear set for a tandem-axle tractor

The Ohio manual warns that low-slung units, including lowboys and car carriers, can become stuck on raised crossings. A long trailer pulled by a single-axle tractor may also hang up if its landing gear is positioned for a tandem-axle tractor. Drivers must evaluate underbody clearance before entering the crossing.

Source: Ohio Commercial Driver License Manual (HSY 7605) — § 6.1.4, “Railroad-highway Crossings”

Question 5

Where are the air-line shut-off valves on a trailer designed to tow another trailer?

  1. A Inside the tractor cab
  2. B At the rear of the tractor
  3. C At the front of the trailer
  4. D At the rear of the trailer

Correct answer: D – At the rear of the trailer

Shut-off valves, also called cut-out cocks, are located in the service and supply lines at the rear of trailers used to tow other trailers. Valves must remain open throughout the combination so air reaches every brake. The valves at the rear of the last trailer must be closed.

Source: Ohio Commercial Driver License Manual (HSY 7605) — § 6.2.7, “Shut-off Valves”

Question 6

How should the trailer hand valve be used during normal driving?

  1. A It should not be used; it is intended for testing the trailer brakes
  2. B It should be applied before the foot brake to prevent skids
  3. C It should replace the foot brake during straight-line stops
  4. D It should be used as the primary brake while turning

Correct answer: A – It should not be used; it is intended for testing the trailer brakes

The trailer hand valve, also called a trolley valve or Johnson bar, should be used only to test the trailer brakes. Applying only the trailer brakes while driving can cause the trailer to skid. The foot brake applies the brakes throughout the combination and creates less danger of a skid or jackknife.

Source: Ohio Commercial Driver License Manual (HSY 7605) — § 6.2.1, “Trailer Hand Valve”

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