CDL Tank Vehicles Practice Test

25 practice questions

Choose an answer, then check it under Show answer.

1. Question 1 of 25Easy

   Under commercial driving rules, hauling liquids or gases in a leaking tank vehicle is:

   1. AA. A minor infraction
   2. BB. A standard exception
   3. CC. A crime
   4. DD. An excusable delay
   Show answer to question 1

   Answer: C. A crime

   Carrying liquids or gases in a leaking tank is a crime. A leaking tank vehicle is not treated as a minor infraction or an excusable delay; the driver will be cited and prevented from driving further.

2. Question 2 of 25Medium

   When driving an empty tank vehicle rather than a fully loaded one, which stopping hazard should you anticipate?

   1. AA. The empty vehicle cannot safely use controlled or stab braking.
   2. BB. The empty vehicle may take longer to stop than a full one.
   3. CC. The empty vehicle will stop in less than half the normal distance.
   4. DD. The empty vehicle will experience twice as much liquid surge.
   Show answer to question 2

   Answer: B. The empty vehicle may take longer to stop than a full one.

   Empty tank vehicles may take longer to stop than full ones because the lack of cargo weight reduces traction between the tires and the roadway. Drivers often assume that an empty vehicle always stops much faster, but reduced tire grip can lead to longer stopping distances or skids.

3. Question 3 of 25Medium

   During your inspection you find a manhole cover that has no gasket and does not close correctly. What should you do?

   1. AA. Cover the opening with a tarp and continue
   2. BB. Drive the vehicle only on routes without sharp turns
   3. CC. Leave it as it is and note it after the trip
   4. DD. Have the cover fitted with a gasket and closing correctly before driving
   Show answer to question 3

   Answer: D. Have the cover fitted with a gasket and closing correctly before driving

   Manhole covers must have gaskets and must close correctly, so a cover in this condition has to be put right before the vehicle is driven. Choosing easier routes or noting the problem later does not make the vehicle safe. The cover itself must meet the requirement.

4. Question 4 of 25Medium

   Which is the correct way to come to a stop in a tank vehicle?

   1. AA. Brake in short, hard jabs and release the brakes between them.
   2. BB. Brake lightly at first, then increase pressure sharply at the end.
   3. CC. Brake far in advance and keep steady pressure on the brakes.
   4. DD. Brake late and hard, then release the brakes as the vehicle slows.
   Show answer to question 4

   Answer: C. Brake far in advance and keep steady pressure on the brakes.

   To control surge, the manual says to brake far in advance of a stop and keep steady pressure on the brakes. Releasing the brakes too soon as the vehicle slows is the tempting mistake, because the liquid keeps pushing the vehicle forward.

5. Question 5 of 25Easy

   What should you check the tank's body or shell for during an inspection?

   1. AA. Paint color and decals
   2. BB. Tire tread depth
   3. CC. Mirror adjustment
   4. DD. Dents or leaks
   Show answer to question 5

   Answer: D. Dents or leaks

   The manual specifically says to check the tank's body or shell for dents or leaks. Paint color, tire tread, and mirror adjustment are not the tank shell checks described for tank vehicles.

6. Question 6 of 25Medium

   Why must a driver inspect special purpose equipment, such as emergency shut-off systems and vapor recovery kits, before a trip?

   1. AA. To verify that the equipment works properly
   2. BB. To drain excess condensation from the lines
   3. CC. To balance liquid surge inside compartments
   4. DD. To calibrate the chassis weight distribution
   Show answer to question 6

   Answer: A. To verify that the equipment works properly

   The CDL manual states that if your vehicle has special purpose equipment such as emergency shut-offs or vapor recovery kits, you must make sure that it works. This equipment is designed for safety and containment, not for altering chassis weight or controlling liquid surge.

7. Question 7 of 25Medium

   After loading, you find liquid dripping from under the tank. What should you do?

   1. AA. Drive slowly to the nearest repair shop
   2. BB. Move it if the drip is small and the valves are shut
   3. CC. Keep the vehicle parked until the leak is fixed
   4. DD. Drain the product onto the ground and go
   Show answer to question 7

   Answer: C. Keep the vehicle parked until the leak is fixed

   The manual states that you must not carry liquids or gases in a leaking tank; doing so is a crime, and you will be cited and prevented from driving further. A small drip with closed valves is still a leak, so moving the vehicle for repairs or for delivery is not allowed.

8. Question 8 of 25Medium

   Which statement about stopping a tank vehicle is correct?

   1. AA. Wet roads shorten stopping distance because the tires grip better.
   2. BB. Stopping distance is the same whether the tank is full or empty.
   3. CC. Wet roads double the normal stopping distance.
   4. DD. A full tank always takes longer to stop than an empty one.
   Show answer to question 8

   Answer: C. Wet roads double the normal stopping distance.

   The manual states that wet roads double the normal stopping distance. It also notes that empty tank vehicles may take longer to stop than full ones, so assuming a full tank is always harder to stop is wrong.

9. Question 9 of 25Medium

   Which of these is special purpose equipment that you must make sure works before driving a tank vehicle?

   1. AA. A vapor recovery kit
   2. BB. The air horn
   3. CC. A backup alarm
   4. DD. The trailer landing gear
   Show answer to question 9

   Answer: A. A vapor recovery kit

   The CDL manual lists vapor recovery kits, grounding and bonding cables, emergency shut-off systems, and built in fire extinguishers as special purpose equipment to check and make sure works. A backup alarm or air horn may be on the vehicle, but neither is on that list.

10. Question 10 of 25Medium

    You must make a quick stop to avoid a crash in a tank vehicle. Which braking method should you use?

    1. AA. Light, steady pressure until the wheels lock up
    2. BB. Releasing the brakes as soon as the liquid surges
    3. CC. Braking only with the trailer hand valve
    4. DD. Controlled or stab braking
    Show answer to question 10

    Answer: D. Controlled or stab braking

    The manual says that if you must make a quick stop to avoid a crash, you should use controlled or stab braking. Letting the wheels lock up with light steady pressure is not the recommended method for an emergency stop, and releasing the brakes when the liquid surges does not control the stop.

11. Question 11 of 25Medium

    How does a driver find out what special items to check on a particular tank vehicle?

    1. AA. By reading the posted speed limit signs
    2. BB. By asking the shipper at the loading rack
    3. CC. By reading the vehicle's operator manual
    4. DD. By checking the bill of lading for the cargo
    Show answer to question 11

    Answer: C. By reading the vehicle's operator manual

    Tank vehicles come in many types and sizes, so the manual says to check the vehicle's operator manual to know how to inspect your tank vehicle. The bill of lading describes the cargo, not the inspection steps for the vehicle.

12. Question 12 of 25Easy

    Why should you check the pipes, connections, and hoses on a tank vehicle, especially around the joints?

    1. AA. To test the vehicle's horn
    2. BB. To confirm the tank is full
    3. CC. To measure the tank capacity
    4. DD. To find leaks in the system
    Show answer to question 12

    Answer: D. To find leaks in the system

    The CDL manual says to check pipes, connections, and hoses for leaks, especially around joints. Confirming that the tank is full is not the purpose of this check.

13. Question 13 of 25Easy

    Your tank vehicle begins to skid. What action should you take?

    1. AA. Take action to restore traction to the wheels.
    2. BB. Brake hard to stop the wheels from sliding.
    3. CC. Accelerate to pull the vehicle out of the skid.
    4. DD. Steer sharply in the opposite direction of the skid.
    Show answer to question 13

    Answer: A. Take action to restore traction to the wheels.

    The manual says that when any vehicle starts to skid, you must take action to restore traction to the wheels. Over braking, over accelerating, and over steering are the very actions that cause a skid, so doing more of them makes the skid worse.

14. Question 14 of 25Easy

    Why must the driver of a liquid tanker be very familiar with how the vehicle handles?

    1. AA. The cargo expands when the tank is completely full.
    2. BB. The tank's weight changes whenever a valve is opened.
    3. CC. The baffles make steering harder at higher speeds.
    4. DD. Liquid movement can have bad effects on handling.
    Show answer to question 14

    Answer: D. Liquid movement can have bad effects on handling.

    The manual says liquid surge results from movement in partially filled tanks and can have bad effects on handling, so the driver must know the vehicle well. Cargo expansion is a real tank concern, but it does not explain why handling familiarity is required.

15. Question 15 of 25Easy

    Besides a high center of gravity, what cargo behavior makes driving a tanker demanding?

    1. AA. Gradual expansion against the chassis
    2. BB. Movement of the liquid inside the tank
    3. CC. Rapid evaporation through the vents
    4. DD. Loss of liquid density during transit
    Show answer to question 15

    Answer: B. Movement of the liquid inside the tank

    The CDL manual specifically identifies liquid movement along with a high center of gravity as the reasons hauling liquids in tanks requires special driving skills. Liquid cargo does not lose density or cause structural chassis expansion during typical travel.

16. Question 16 of 25Hard

    A hazard appears and you brake hard. Avoiding it would also require you to steer quickly. Why is this dangerous in a tank vehicle?

    1. AA. The brakes may overheat and stop working completely.
    2. BB. The surge will make the steering wheel impossible to hold.
    3. CC. The rear axle may lose its air supply.
    4. DD. The vehicle may roll over.
    Show answer to question 16

    Answer: D. The vehicle may roll over.

    If you steer quickly while braking, your vehicle may roll over because of the high center of gravity and the moving liquid. Overheating brakes or losing air supply are not what the manual warns about in this situation; the danger is the rollover.

17. Question 17 of 25Hard

    Why can side-to-side surge still occur in a baffled liquid tank?

    1. AA. The holes in the baffles block all liquid flow.
    2. BB. The baffles are too small to slow any liquid.
    3. CC. The baffles control forward and backward surge only.
    4. DD. The baffles are removed before loading.
    Show answer to question 17

    Answer: C. The baffles control forward and backward surge only.

    Baffled tanks have bulkheads with holes that let liquid flow through. The baffles help control forward and backward liquid surge, but side-to-side surge can still occur and may cause a rollover. Holes in the baffles let liquid pass rather than blocking all flow.

18. Question 18 of 25Hard

    A tank used to haul liquid is temporarily attached to the vehicle rather than permanently mounted. How does this affect the tank endorsement requirement?

    1. AA. It still applies if the tank capacities meet the thresholds
    2. BB. The tank endorsement is needed only when the tank carries gas
    3. CC. The tank endorsement is needed only for permanently mounted tanks
    4. DD. No tank endorsement is needed because the tank is temporary
    Show answer to question 18

    Answer: A. It still applies if the tank capacities meet the thresholds

    The manual covers tanks that are permanently or temporarily attached to the vehicle or chassis. Temporary mounting does not remove the endorsement requirement.

19. Question 19 of 25Hard

    You must make a quick stop to avoid a crash. What should you do?

    1. AA. Pump the brake pedal fast while steering toward the shoulder.
    2. BB. Use controlled or stab braking; avoid quick steering while braking.
    3. CC. Brake hard and steer quickly at once to turn around the hazard.
    4. DD. Release the brakes and steer sharply aside, then brake again.
    Show answer to question 19

    Answer: B. Use controlled or stab braking; avoid quick steering while braking.

    For a quick stop to avoid a crash, the manual says to use controlled or stab braking. It also warns that steering quickly while braking may roll the vehicle over, so braking hard while steering sharply is dangerous.

20. Question 20 of 25Easy

    What mistake is made if a driver loads a cargo tank completely full with liquid?

    1. AA. Exceeding the maximum legal height limit for bulk cargo
    2. BB. Failing to leave room for the liquid to expand as it warms
    3. CC. Forcing liquid to overflow through the emergency cut-off
    4. DD. Preventing the intake valves from closing and sealing shut
    Show answer to question 20

    Answer: B. Failing to leave room for the liquid to expand as it warms

    Liquids expand as they warm, so a cargo tank must never be loaded completely full. Leaving empty space for this expansion is called outage, and running without outage risks tank overpressure or spills. Loading a tank completely full does not change vehicle height limits or block the intake valves from closing.

21. Question 21 of 25Hard

    Why might a driver of a Class A or B vehicle need a tank endorsement even if the cargo is NOT hazardous?

    1. AA. The tanks meet the individual and aggregate capacity thresholds.
    2. BB. Any portable container attached to a chassis requires an endorsement.
    3. CC. Non-hazardous liquids produce higher vapor pressure during transit.
    4. DD. Non-hazardous loads cause more liquid movement than hazardous loads.
    Show answer to question 21

    Answer: A. The tanks meet the individual and aggregate capacity thresholds.

    The manual states that the liquid or gas does not have to be hazardous to require a tank endorsement; an endorsement is required for Class A or B vehicles if the tank capacity is more than 119 gallons individually and 1,000 gallons or more in aggregate. Non-hazardous cargo does not generate higher vapor pressure or behave with greater surge than hazardous liquids.

22. Question 22 of 25Medium

    Why must the vents on a tank vehicle be kept clear?

    1. AA. So the manhole covers will latch
    2. BB. So the vents will work correctly
    3. CC. So the tank can be filled faster
    4. DD. So rain water stays out of the tank
    Show answer to question 22

    Answer: B. So the vents will work correctly

    The CDL manual says to keep the vents clear so they work correctly. Keeping rain water out is not the stated purpose of clearing the vents, and cover latching depends on the gaskets and covers themselves.

23. Question 23 of 25Medium

    Why must a driver take highway curves and ramp curves well below posted speeds in a liquid tanker?

    1. AA. Liquid cargo can leak out of normal pressure relief vents.
    2. BB. Tests show tankers can turn over at posted curve speeds.
    3. CC. Trailer anti-lock brakes will disengage on sharp turns.
    4. DD. Centrifugal force will cause tank discharge valves to open.
    Show answer to question 23

    Answer: B. Tests show tankers can turn over at posted curve speeds.

    Liquid tankers have a high center of gravity, and tests have shown that they can turn over even at the posted speed limits for curves. Drivers often assume that posted curve limits are safe for all traffic, but tankers must travel well below them to prevent rollovers.

24. Question 24 of 25Hard

    When calculating how much liquid can safely be loaded into a tank, which factor must be taken into account to avoid hazards?

    1. AA. The number of axles on other traffic nearby
    2. BB. The horsepower rating of the tractor engine
    3. CC. The total volume capacity of the tractor fuel tanks
    4. DD. The amount the liquid will expand in transit
    Show answer to question 24

    Answer: D. The amount the liquid will expand in transit

    The amount of liquid to load depends on how much the liquid will expand in transit, the weight of the liquid, and legal weight limits. If expansion is ignored, the tank can become overfilled or overpressurized as temperatures change. Tractor engine horsepower has no role in determining safe tank loading limits.

25. Question 25 of 25Hard

    Why must a driver check that tank manhole covers have gaskets and close correctly before driving?

    1. AA. To prevent leaks and ensure the tank does not remain open while driving
    2. BB. To increase the aggregate rated capacity of the tank during transport
    3. CC. To allow vapor recovery systems to vent directly to the atmosphere
    4. DD. To eliminate the high center of gravity caused by the liquid cargo
    Show answer to question 25

    Answer: A. To prevent leaks and ensure the tank does not remain open while driving

    The CDL manual specifies that covers must have gaskets and close correctly, and warns never to drive with open valves or manhole covers to prevent liquid from escaping. Gaskets and closed covers provide a proper seal, but they cannot eliminate the high center of gravity or increase tank capacity.

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The full CDL bank has 77 Tank Vehicles questions. See plans