CCDL Permit Prep

Tank Vehicles · page 2 of 3

Tank Vehicles questions 21–40

Part of the 55-question Tank Vehicles pool. Each answer cites the FMCSA CDL Manual or the federal rule it comes from.

Practise these as a timed set

  1. Which tank-vehicle inspection item is a special leak point that a box trailer does not have?

    • ATheir tires never need checking
    • BThey have no lights to check
    • CManholes, vents, valves, and caps must be checked for leaksCorrect
    • DThey carry no shipping papers

    FMCSA Section 8.1.1 says to check the tank shell, valves, pipes, connections, hoses, manhole covers, and vents for leaks or correct operation. These tank-specific leak points require deliberate inspection; follow the vehicle operator manual for the exact procedure.

    FMCSA Commercial Driver License Manual · Section 8.1.1: Leaks (tank shell, valves, pipes, connections, hoses, manhole covers, and vents) · verified 2026-09-08

  2. What does it mean that a tank is loaded to its legal weight but not full?

    • AThe baffles blocked the flow
    • BThe tank has a manufacturing fault
    • CThe pump stopped working early
    • DA dense liquid reaches the weight limit firstCorrect

    FMCSA says a full tank of dense liquid may exceed legal weight limits. The amount to load depends on liquid expansion, liquid weight, and legal weight limits, so a tank may reach its legal weight before it is physically full.

    FMCSA Commercial Driver License Manual · Section 8.2.7: How Much to Load? · verified 2026-09-08

  3. For an on-vehicle manual remote shutoff device covered by 49 CFR 172.328(d), how must the device be identified?

    • AMarked “Emergency Shutoff” immediately adjacent to the means of closureCorrect
    • BMarked “Brake Release” on the trailer frame
    • CMarked only on the shipping paper
    • DLeft unmarked to prevent unauthorized use

    For a covered on-vehicle manually activated remote shutoff device, 49 CFR 172.328(d) requires “Emergency Shutoff” marking in contrasting letters at least 0.75 inch high in an area immediately adjacent to the means of closure.

    eCFR 49 CFR 172.328 · 172.328(d): Emergency shutoff marking · verified 2026-09-07

  4. Why should a tank-vehicle start be smooth?

    • AThe trailer brakes apply briefly
    • BThe load stays completely still
    • CThe tank pressure drops sharply
    • DA smooth start helps control liquid surge and the vehicle's handlingCorrect

    FMCSA says liquid surge in a partially filled tank affects handling and that drivers must start, slow down, and stop smoothly because of the liquid's surge and the tank vehicle's high center of gravity.

    FMCSA Commercial Driver License Manual · Section 8.2.2: Danger of Surge; Section 8.3.1: Drive Smoothly · verified 2026-09-08

  5. Before moving a tank vehicle after loading, what should the driver confirm about its closures and vents?

    • ACargo valves and manhole covers are secured for travel, and vents are clear and workingCorrect
    • BLeave a manhole open to avoid pressure buildup
    • CBlock the vents to prevent vapor escape
    • DLeave a discharge valve open if the trip is short

    Check valves in the proper travel position and covers correctly closed. Keep vents functional; do not confuse securing cargo closures with blocking required venting.

    Oregon DMV Commercial Driver Manual · 8.1.1–8.1.2 · verified 2026-09-07

  6. Why should a liquid-tanker driver leave extra following space?

    • AEvery tanker has a weaker engine
    • BMirror position sets braking distance
    • CThe extra room allows earlier, smoother stops while managing surgeCorrect
    • DEvery tanker has narrower tires

    Leave room to brake well before a stop. Do not rely on a fixed stopping-distance comparison with a box trailer; vehicle, load, road, and braking conditions vary.

    Oregon DMV Commercial Driver Manual · 8.3.2; 8.3.4 · verified 2026-09-07

  7. What should you check about a tank's venting system?

    • AVents are painted the same color
    • BVents are sealed with tape
    • CVents point toward the cab
    • DVents are clear and working freelyCorrect

    FMCSA Section 8.1.1 says to check manhole covers and vents, make sure covers have gaskets and close correctly, and keep vents clear so they work correctly. Use the vehicle operator manual for any additional inspection steps.

    FMCSA Commercial Driver License Manual · Section 8.1.1: Leaks (manhole covers and vents) · verified 2026-09-08

  8. Before loading, unloading, or driving a tanker, what should the driver do?

    • AInspect the vehicle to confirm it is safe to carry the liquid or gas and safe to driveCorrect
    • BOpen the manhole covers to equalize pressure
    • CSkip the inspection if the tank is empty
    • DRely on the shipper's inspection instead

    FMCSA Section 8 says to inspect a tank vehicle before loading, unloading, or driving so it is safe to carry the liquid or gas and safe to drive.

    FMCSA Commercial Driver License Manual · Section 8: Tank Vehicles, introduction to inspection · verified 2026-09-08

  9. What marking must a specification cargo tank show?

    • AThe driver's license expiration date
    • BA re-test date markingCorrect
    • CThe route permit renewal date
    • DThe paint renewal date

    FMCSA Section 9.5.1 says specification cargo tanks must show re-test date markings.

    FMCSA Commercial Driver License Manual · Section 9.5.1: Bulk Packaging Markings · verified 2026-09-08

  10. Why are liquid tankers especially easy to roll over?

    • ATheir high center of gravity and liquid movement make them top-heavyCorrect
    • BTheir tanks are always empty on curves
    • CTheir tires are narrower than passenger-car tires
    • DTheir engines stop automatically in a turn

    FMCSA Section 8.2.1 says the high center of gravity and liquid movement make tankers top-heavy and especially easy to roll over.

    FMCSA Commercial Driver License Manual · Section 8.2.1: High Center of Gravity · verified 2026-09-08

  11. Before loading, unloading, or moving a tank vehicle, what should you check about its intake, discharge, and cut-off valves?

    • AThat they are in the correct positionCorrect
    • BThat they are painted the same color as the cab
    • CThat they are left open during movement
    • DThat they are removed before inspection

    FMCSA Section 8.1.1 says to check the intake, discharge, and cut-off valves and make sure they are in the correct position before loading, unloading, or moving the vehicle.

    FMCSA Commercial Driver License Manual · Section 8.1.1: Leaks · verified 2026-09-08

  12. What should you check about a tank's pipes, connections, and hoses?

    • ACheck for leaks, especially around jointsCorrect
    • BInspect them only after loading
    • CLeave the connections open while moving
    • DReplace every hose before each trip

    FMCSA Section 8.1.1 says to check pipes, connections, and hoses for leaks, especially around joints.

    FMCSA Commercial Driver License Manual · Section 8.1.1: Leaks · verified 2026-09-08

  13. Why must a cargo tank not be loaded totally full?

    • ALiquids expand as they warm, so room must be left for the expanding liquidCorrect
    • BA full tank always loses its brakes
    • CThe driver must keep the tank empty on every trip
    • DThe cargo tank cannot be weighed when full

    FMCSA Section 8.2.6 says never to load a cargo tank totally full because liquids expand as they warm; the driver must leave room for expansion, called outage.

    FMCSA Commercial Driver License Manual · Section 8.2.6: Outage · verified 2026-09-08

  14. Which item does FMCSA list among tank-vehicle special-purpose equipment to check?

    • AVapor recovery kitsCorrect
    • BA passenger seating chart
    • CA route mileage log
    • DA cargo invoice printer

    FMCSA Section 8.1.2 lists vapor recovery kits among the special-purpose equipment to check and make sure works.

    FMCSA Commercial Driver License Manual · Section 8.1.2: Check Special Purpose Equipment · verified 2026-09-08

  15. What should be done with discharge valves before driving away?

    • ALeft open to relieve pressure
    • BClosed and confirmed secureCorrect
    • CRemoved and stored in the cab
    • DWrapped in protective tape

    FMCSA Section 9.5.2 says to close all manholes and valves before moving a hazardous-materials tank; open valves can cause leaks.

    FMCSA Commercial Driver License Manual · Section 9.5.2: Tank Loading and Unloading · verified 2026-09-08

  16. How far from a placarded cargo tank used for Class 3 or Division 2.1 materials must you avoid smoking?

    • A5 feet
    • B10 feet
    • C25 feetCorrect
    • D100 feet

    FMCSA Section 9.6.6 says not to smoke within 25 feet of a placarded cargo tank used for Class 3 flammable liquids or Division 2.1 gases.

    FMCSA Commercial Driver License Manual · Section 9.6.6: No Smoking · verified 2026-09-08

  17. What should you check about a tank vehicle's manhole covers and vents?

    • AThat the covers have gaskets, close correctly, and the vents stay clearCorrect
    • BThat the covers remain open while driving
    • CThat the vents are sealed with tape
    • DThat the covers are removed before loading

    FMCSA Section 8.1.1 says to check manhole covers and vents, make sure covers have gaskets and close correctly, and keep vents clear so they work correctly.

    FMCSA Commercial Driver License Manual · Section 8.1.1: Leaks · verified 2026-09-08

  18. What should you verify about a tank vehicle's vents?

    • AThey are clear and work correctlyCorrect
    • BThey are sealed with tape
    • CThey are removed before loading
    • DThey are used as fill openings

    FMCSA Section 8.1.1 says to keep tank vents clear so they work correctly. Manhole-cover gaskets and closure are separate checks.

    FMCSA Commercial Driver License Manual · Section 8.1.1: Leaks · verified 2026-09-08

  19. What causes liquid surge in a tank vehicle?

    • AMovement of liquid in a partially filled tankCorrect
    • BA full tank having no liquid movement
    • CThe tank's paint changing color
    • DThe parking brake holding the vehicle

    FMCSA Section 8.2.2 says liquid surge results from movement of the liquid in partially filled tanks and can affect handling.

    FMCSA Commercial Driver License Manual · Section 8.2.2: Danger of Surge · verified 2026-09-08

  20. If a flammable-liquid cargo tank leaks en route, what should the driver do?

    • AContinue only until the scheduled delivery
    • BTransfer the liquid to another vehicle on the roadway
    • CKeep bystanders away, get off the roadway if safe, and go no farther than needed to reach a safe placeCorrect
    • DOpen the valve fully to release the pressure

    FMCSA Section 9.6.13 says to keep bystanders away, never transport a leaking cargo tank farther than needed to reach a safe place, and get off the roadway if possible.

    FMCSA Commercial Driver License Manual · Section 9.6.13: Flammable Liquid Emergencies · verified 2026-09-08