CDL Tank Vehicles Sample Questions

Questions from each area of the CDL Tank Vehicles test. Pick an answer to see whether you're right, how everyone else did, and why.

CDL Tank Vehicles Test exam guide

1 Causes, prevention, and effects of cargo surge on motor vehicle handling

What two things make a liquid tanker hard to drive safely?

  1. The tank has many valves, and the hoses need checking.
  2. The load is very heavy, and the liquid is hazardous.
  3. The load sits high, and the liquid moves around.

Answer: C, The load sits high, and the liquid moves around.. When the weight rides high, a tanker tips over more easily. The liquid can also surge, or slosh, and push the truck around. Both make the tanker harder to control. (CDL manual 8.2)

Because liquid surge affects handling, the driver of a liquid tanker must:

  1. carry a hazardous materials endorsement.
  2. load each tank up to the top.
  3. know well how the vehicle handles.

Answer: C, know well how the vehicle handles.. Surge changes how a tanker starts, stops and turns. The driver must know the vehicle's handling very well to stay in control. (CDL manual 8.2.2)

2 Proper braking procedures for the motor vehicle when it is empty, full, and partially full

You are braking hard in a partly full tank truck and steer quickly to miss a car. What may happen?

  1. The truck may roll over onto its side.
  2. The truck may stop in a shorter distance.
  3. The liquid may stop surging so much.

Answer: A, The truck may roll over onto its side.. A tanker is top-heavy, and its liquid can surge to the side. A quick turn of the wheel while braking can tip it over. (CDL manual 8.3.2)

You are driving an empty tank vehicle. Compared with a full load, your stopping distance may be:

  1. longer, because the empty truck has less traction.
  2. shorter, because the empty truck weighs less.
  3. None of the above.

Answer: A, longer, because the empty truck has less traction.. Truck brakes and suspension work best with a full load. An empty truck presses less on the road, so its tires grip less and it can need more room to stop. (CDL manual 8.3.4, 2.6.1)

3 Differences in handling of baffled/compartmented tank interiors versus non-baffled motor vehicles

Inside a liquid tank, bulkheads are used to:

  1. leave space at the top for the liquid to expand.
  2. divide it into several separate compartments.
  3. stop the liquid from surging side to side.

Answer: B, divide it into several separate compartments.. Bulkheads are walls that split one tank into several smaller tanks, called compartments. Each one can be filled or emptied by itself. (CDL manual 8.2.3)

Inside a baffled tank, the baffles are:

  1. solid walls that split the tank into sealed sections.
  2. walls with holes so the liquid can flow through.
  3. pipes that carry vapor out of the tank as it warms.

Answer: B, walls with holes so the liquid can flow through.. A baffle is a wall inside the tank with holes in it. The liquid can still pass through the holes, but the wall slows it down. (CDL manual 8.2.4)

4 Differences in tank vehicle type and construction

Tank vehicles vary a lot. Where should you learn how to inspect the one you drive?

  1. In the CDL manual's pre-trip checklist
  2. In the vehicle's operator's manual
  3. On the tank's specification plate

Answer: B, In the vehicle's operator's manual. Tankers come in many designs, each with its own valves and equipment. The operator's manual for your vehicle tells you how to inspect that tanker. (CDL manual 8.1)

What is another name for an un-baffled liquid tank?

  1. A smooth bore tank
  2. A dry bulk tank
  3. A compartment tank

Answer: A, A smooth bore tank. An un-baffled tank is called a smooth bore tank because its inside is smooth and empty, with no baffles. (CDL manual 8.2.5)

5 Differences in cargo surge for liquids of varying product densities

When you haul a very heavy liquid, how full do you often fill the tank?

  1. To the top, so the liquid has no room to surge.
  2. To the tank's full gallon rating, less outage.
  3. Part way, to stay under the weight limit.

Answer: C, Part way, to stay under the weight limit.. A full tank of heavy liquid can weigh more than the law allows. So these tanks are often filled only part way. (CDL manual 8.2.7)

A tank of heavy liquid is often loaded only part way. The driver should expect:

  1. surge in a smooth bore tank, but not in a baffled one.
  2. little surge, because a heavy liquid is slow to move.
  3. surge, because the tank has open space inside.

Answer: C, surge, because the tank has open space inside.. Heavy liquids are often loaded part way to stay under weight limits. The open space lets the liquid move, which causes surge when you start, stop or turn (CDL manual 8.2.2, 8.2.7).

6 Effects of road grade and curvature on motor vehicle handling with filled, half-filled, and empty tanks

You are driving a loaded tanker onto a curved off-ramp. What speed should you use?

  1. the posted ramp speed
  2. well below the posted ramp speed
  3. the speed of the traffic ahead of you

Answer: B, well below the posted ramp speed. A tanker can roll over even at the posted speed for a curve. Take ramp curves at a speed well under the one on the sign. (CDL manual 8.2.1)

Gravity speeds you up on a downgrade, so pick a speed that suits:

  1. the total weight of the truck and its load, and how long and steep the grade is.
  2. the posted truck speed limit and the speed of the traffic around you.
  3. the power of your engine and the time you need to stay on schedule.

Answer: A, the total weight of the truck and its load, and how long and steep the grade is.. A heavy load on a long, steep hill picks up speed fast. Choose a speed your brakes and engine can hold for that weight and that hill. Road conditions and weather matter too. (CDL manual 2.6.6)

7 Proper use of emergency systems

Once you know what emergency equipment your vehicle is required to have, you should:

  1. check that each item was inspected and logged by the shop.
  2. check that each item is on board and working.
  3. check that each item is listed and signed for on your papers.

Answer: B, check that each item is on board and working.. Equipment only helps if it is on the vehicle and ready to use. Before you drive, see each item for yourself and check that it works. Examples are the fire extinguisher and the warning triangles. (CDL manual 8.1.3)

On a cargo tank used for gasoline, carrying fusees is banned:

  1. while the tank is full or partly full
  2. whether the tank is loaded or empty
  3. until the tank is washed or steam cleaned

Answer: B, whether the tank is loaded or empty. Fusees and other flame signals may never ride on a cargo tank used for flammable liquid or flammable gas. An empty tank can still hold vapors that burn. Use reflective triangles instead. (49 CFR 393.95(g))

8 For drivers of DOT specification tank vehicles, retest and marking requirements

A DOT specification cargo tank has not hauled hazmat for 14 months. What test must it pass before it hauls hazmat again?

  1. A leakage test
  2. An external visual inspection
  3. A pressure test

Answer: C, A pressure test. A cargo tank that has been out of hazmat service for 1 year or more must pass a pressure test before it is used again. (49 CFR 180.407(b)(3))

You haul gasoline in a DOT specification cargo tank. It must pass an external visual inspection and a leakage test:

  1. every year.
  2. every 2 years.
  3. every 6 months.

Answer: A, every year.. Most specification cargo tanks, including fuel tanks, need an external visual inspection and a leakage test once a year. (49 CFR 180.407(c))

9 Operating practices and procedures not otherwise specified

When you load liquid into a cargo tank, you should:

  1. never fill it completely.
  2. fill it completely to stop surge.
  3. leave space only when it is hot.

Answer: A, never fill it completely.. Liquids get bigger as they warm up, so a cargo tank always needs some empty space. This space is called outage. (CDL manual 8.2.6)

When your tank vehicle starts to skid, you must act to:

  1. get the wheels gripping the road again.
  2. stop the truck as fast as you can.
  3. keep the liquid from surging in the tank.

Answer: A, get the wheels gripping the road again.. A skid means the tires have lost their grip on the road. Your job is to get that grip back, for example by easing off the brake or the accelerator. (CDL manual 8.3.5)