CCDL Permit Prep

Tank Vehicles · page 3 of 3

Tank Vehicles questions 41–55

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 special-purpose equipment should work on a tank vehicle, if equipped?

    • AVapor recovery kits, grounding and bonding cables, emergency shut-off systems, and built-in fire extinguishersCorrect
    • BOnly a spare tire and a cargo tarp
    • COnly a windshield scraper and work gloves
    • DOnly a second fuel tank

    FMCSA Section 8.1.2 lists vapor recovery kits, grounding and bonding cables, emergency shut-off systems, and built-in fire extinguishers as special-purpose equipment to check when present.

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

  2. A liquid tanker is partly loaded. What should the driver assume about stopping?

    • AIt must stop sooner than the same tank at every fuller load
    • BIt will stop exactly like an empty tank
    • CSurge can affect the stop, so allow extra room and avoid a fixed fill-level comparisonCorrect
    • DThe load cannot affect stopping

    A partial load can surge. Plan an early, smooth stop and leave extra following distance; fill level alone does not establish a reliable stopping distance.

    Oregon DMV Commercial Driver Manual · 8.2.2; 8.3.2; 8.3.4 · verified 2026-09-07

  3. What should a driver do about a hazardous-materials tank's manholes and covers before moving?

    • ATape them shut
    • BLeave one open for pressure
    • CRemove them for the trip
    • DClose them and confirm they are secureCorrect

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

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

  4. What should you check on a tank vehicle's body or shell?

    • ADents or leaksCorrect
    • BThe previous driver's name
    • CThe route printed on the cab
    • DThe color of the last load

    FMCSA Section 8.1.1 says to check the tank's body or shell for dents or leaks before operating it.

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

  5. What is the safe response if a liquid cargo tank is loaded totally full?

    • AOpen a cover to relieve pressure
    • BDrive slowly to the destination
    • CVent the liquid along the route
    • DDo not move it until the load is corrected to leave room for expansionCorrect

    FMCSA Section 8.2.6 says never to load a cargo tank totally full because liquids expand as they warm and require outage.

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

  6. How does temperature affect a liquid load in transit?

    • AWarming expands it and requires outageCorrect
    • BCooling increases its volume
    • CTemperature has no effect
    • DHeat reduces the surge

    FMCSA Section 8.2.6 says liquids expand as they warm, so a cargo tank must leave room called outage for that expansion.

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

  7. What should you do before driving a tank vehicle with valves or manhole covers?

    • AMake sure the valves and manhole covers are closedCorrect
    • BLeave every valve open to equalize pressure
    • CRemove the manhole covers for ventilation
    • DTape the covers shut without checking them

    FMCSA Sections 8.1.2 and 9.5.2 require valves and manhole covers to be closed before moving a tank vehicle; open valves or covers can allow leaks.

    FMCSA Commercial Driver License Manual · Sections 8.1.2 and 9.5.2: Special Purpose Equipment and Tank Loading · verified 2026-09-08

  8. What should you do if a tank vehicle is leaking?

    • ADo not carry liquids or gases in itCorrect
    • BContinue if the load is light
    • CTape over the leak and continue
    • DIncrease the tank pressure

    FMCSA Section 8.1.1 says not to carry liquids or gases in a leaking tank; the driver may be cited and prevented from driving further.

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

  9. What maximum allowable working-pressure range does 49 CFR specify for a DOT-406 cargo tank?

    • AAt least 2.65 psig and no more than 4 psigCorrect
    • BAt least 25 psig and no more than 50 psig
    • CAt least 100 psig and no more than 200 psig
    • DNo maximum allowable working pressure applies

    For a DOT-406 cargo tank, the maximum allowable working pressure must be no lower than 2.65 psig and no higher than 4 psig. The specification does not by itself identify one fuel or product that the tank normally carries.

    eCFR 49 CFR 178.346 · 49 CFR 178.346-1(b): DOT-406 MAWP · verified 2026-09-08

  10. What is the most important item to check on all tank vehicles?

    • ALeaksCorrect
    • BThe driver's route schedule
    • CThe color of the cab
    • DThe last delivery time

    FMCSA Section 8.1.1 says the most important item to check on all tank vehicles is leaks; do not carry liquids or gases in a leaking tank.

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

  11. What should you do before loading a flammable liquid through an open filling hole?

    • AGround the cargo tank correctly and keep it grounded until the filling hole is closedCorrect
    • BLeave the engine running while filling
    • CSkip grounding if the tank is nearly empty
    • DOpen every valve before connecting the hose

    FMCSA Section 9.5.3 says to ground a cargo tank correctly before opening the filling hole and maintain the ground until after closing it.

    FMCSA Commercial Driver License Manual · Section 9.5.3: Flammable Liquids · verified 2026-09-08

  12. Which statement is a safe rule for preventing cargo-tank rollovers?

    • ARollovers are possible only on curves
    • BDriving at a posted speed guarantees stability
    • CSudden steering is harmless on a straight road
    • DControl speed and avoid sudden movements on curves and straight roadsCorrect

    Rollover prevention applies on straight roads as well as curves. Maintain control of speed and use smooth inputs; no posted speed guarantees stability in every condition.

    FMCSA Cargo Tank Truck Rollover Prevention · Rollover prevention: driver actions · verified 2026-09-07

  13. After a cargo-tank rollover with hazardous product leaking, what should an untrained driver do if able to move safely?

    • AGet clear and upwind, warn others away, and call emergency servicesCorrect
    • BTry to right the vehicle with a tow strap
    • COpen the manhole covers
    • DWash the spill toward a drain

    Avoid contact with the release and communicate cargo information from a safe place. Do not attempt recovery or cleanup without the training and equipment needed for the hazard.

    Oregon DMV Commercial Driver Manual · 9.7.2–9.7.3 · verified 2026-09-07

  14. Under 49 CFR 173.29(a), how must an empty packaging containing only hazardous-material residue generally be offered for transportation and transported?

    • AIn the same manner as when it contained a greater quantity of that hazardous materialCorrect
    • BAs non-hazardous cargo as soon as it is empty
    • COnly after all placards automatically expire
    • DOnly if it is below a minimum legal weight

    The general rule applies unless another provision in the section applies. An empty packaging can be excepted only when it meets specified conditions, including being sufficiently cleaned of residue and purged of vapors to remove any potential hazard.

    Electronic Code of Federal Regulations · 49 CFR 173.29(a)-(b) · verified 2026-09-08

  15. A partly loaded tanker stops at a light. What can liquid surge do?

    • ANo difference from solid freight
    • BA smoother stop than a dry van
    • CReduced stopping distance
    • DPush the stopped truck in the direction the liquid wave travelsCorrect

    When a liquid wave reaches a tank end, it tends to push the truck in the direction the wave moves. On a slippery surface, surge can shove a stopped truck into an intersection; plan the stop early and do not release the brakes too soon.

    Oregon Commercial Driver Manual · Section 8.2.2 and 8.3.2: Danger of Surge; Controlling Surge · verified 2026-09-07