For a vehicle requiring a CDL, which attached liquid or gas tank capacities meet the federal tank-vehicle definition?
Correct answer: Each qualifying tank exceeds 119 gallons; combined capacity is at least 1,000 gallons
Use rated capacities, not just the amount currently loaded. Permanent and temporary attachments qualify. An empty storage container tank not designed for transportation, temporarily attached to a flatbed, has a specific exception. Tank vehicles require the tank endorsement; hazardous cargo can require additional authorization.
Source: 49 CFR 383.5, Tank vehicle definition; endorsement requirement in 383.93(b)(3), current eCFR checked September 12, 2026 ↗
What cargo restriction applies to a commercial learner permit holder with a tank endorsement?
Correct answer: The tank must be empty and any previous hazardous-material residue purged
An N-endorsed CLP permits only an empty tank vehicle. A tank that previously contained hazardous material must be purged of residue. Other CLP conditions, including the qualified accompanying CDL holder, still apply.
Source: 49 CFR 383.25(a)(5)(iii), empty tanks and hazardous-material residue; accompanying driver in (a)(1), checked September 12, 2026 ↗
Which cargo-tank defect can make it unsafe to transport a load?
Correct answer: A leaking valve or tank seam
Leaks can make the vehicle unlawful and unsafe to move and can leave the driver responsible for cleanup.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.1.1 Leaks, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
What should a driver do after discovering that a cargo tank is leaking?
Correct answer: Do not transport cargo in it
A leaking tank must not be driven with cargo; doing so is a crime and the vehicle can be placed out of service.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.1.1 Leaks, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
Before loading, unloading, or moving a tank vehicle, what must be verified about its valves?
Correct answer: They are in the correct positions
Intake, discharge, and cutoff valves must be checked for leaks and set correctly for the operation.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.1.1 Leaks, valves, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
What should be checked at tank manhole covers and vents?
Correct answer: Sound gaskets, correctly closed covers, clear vents
Secure gasketed covers prevent leaks, while clear vents must remain able to function.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.1.1 Leaks, manhole covers and vents, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
Which system is special-purpose tanker equipment that must work when installed?
Correct answer: Emergency shutoff system
Vapor recovery, grounding and bonding cables, emergency shutoffs, and built-in extinguishers require inspection.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.1.2 Check Special Purpose Equipment, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
Which cargo-tank condition must be corrected before travel?
Correct answer: Open discharge valve or manhole cover
A tank vehicle must never be driven with valves or manhole covers open.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.1.2 Check Special Purpose Equipment, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
Why are liquid tankers especially vulnerable to rollover?
Correct answer: Their load has a high center of gravity
Much of the load weight is high above the road, making the vehicle top-heavy.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.2.1 High Center of Gravity, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
How should a tanker driver approach highway, entrance-ramp, and exit-ramp curves?
Correct answer: Well below the posted curve speed
Tankers can roll even at posted curve speeds, so the driver must reduce speed well below them.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.2.1 High Center of Gravity, printed page 8-8-1 (as printed) (physical PDF page 107) ↗
What can liquid surge do after a partly filled tanker stops on a slippery road?
Correct answer: Shove the stopped vehicle forward
A moving liquid wave can strike the tank end and shove the vehicle in the wave direction.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.2.2 Danger of Surge (continued), printed page 8-8-2 (as printed) (physical PDF page 108) ↗
When loading a tank divided into separate compartments by bulkheads, what deserves special attention?
Correct answer: Front-to-rear weight distribution
Separate compartments can overload the front or rear if their weight is distributed poorly.
Source: Florida Commercial Driver's License Manual, July 2022, section 8.2.3 Bulkheads, printed page 8-8-2 (as printed) (physical PDF page 108) ↗
