A tank shell looks intact, but liquid is seeping around a discharge-valve connection. Is the vehicle ready to haul the load?
Correct answer: No; valve, pipe, hose, and connection leaks are part of the tank inspection too.
Tank inspection includes the shell, valves, pipes, hoses, covers, and vents. Do not transport a load in a leaking tank system.
Source: Iowa DOT official older Commercial Driver's License Manual, Hy-Brid Version October 2023 with July 2017 technical core; 8.1.1 Leaks; printed 8-1 (printed header displays 8-8-1), physical PDF page 103. Older technical guidance read 2026-10-01, not confirmation of the current media/326 edition, current Iowa qualification law, or current skills-test administration. ↗
A partially filled liquid tanker has just stopped on ice. Why can the vehicle still be pushed forward?
Correct answer: Liquid continuing to surge inside the tank can push against its end.
Liquid in a partly filled tank can continue moving after the vehicle slows or stops. On a slick surface, that surge can move the vehicle.
Source: Iowa DOT official older Commercial Driver's License Manual, Hy-Brid Version October 2023 with July 2017 technical core; 8.2.2 Danger of Surge; continued on physical PDF page 104; printed 8-1–8-2 (printed headers display 8-8-1 and 8-8-2), physical PDF page 103. Older technical guidance read 2026-10-01, not confirmation of the current media/326 edition, current Iowa qualification law, or current skills-test administration. ↗
Your tanker has separate compartments divided by solid bulkheads. What must you consider when deciding which compartments to fill or empty?
Correct answer: How the resulting load distributes weight over the vehicle and its axles.
Bulkheads divide the load into smaller tanks, but uneven filling or unloading can still overload the front or rear. Plan weight distribution throughout the operation.
Source: Iowa DOT official older Commercial Driver's License Manual, Hy-Brid Version October 2023 with July 2017 technical core; 8.2.3 Bulkheads; printed 8-2 (printed header displays 8-8-2), physical PDF page 104. Older technical guidance read 2026-10-01, not confirmation of the current media/326 edition, current Iowa qualification law, or current skills-test administration. ↗
A driver says that tank baffles make abrupt lane changes safe because they control liquid movement. What is wrong with that reasoning?
Correct answer: Baffles reduce forward-and-back surge, but sideways surge can still contribute to rollover.
Openings in baffles allow flow between areas of the tank. They limit longitudinal surge, not all lateral movement or rollover risk.
Source: Iowa DOT official older Commercial Driver's License Manual, Hy-Brid Version October 2023 with July 2017 technical core; 8.2.4 Baffled Tanks; printed 8-2 (printed header displays 8-8-2), physical PDF page 104. Older technical guidance read 2026-10-01, not confirmation of the current media/326 edition, current Iowa qualification law, or current skills-test administration. ↗
You change from a baffled tanker to a smooth-bore tanker. What handling change should you particularly anticipate?
Correct answer: Stronger forward-and-back surge, requiring especially smooth starts and stops.
A smooth-bore tank has no baffles to slow longitudinal liquid flow. Anticipate stops and make gradual control changes.
Source: Iowa DOT official older Commercial Driver's License Manual, Hy-Brid Version October 2023 with July 2017 technical core; 8.2.5 Un-baffled Tanks and 8.3.1 Drive Smoothly; printed 8-2 (printed header displays 8-8-2), physical PDF page 104. Older technical guidance read 2026-10-01, not confirmation of the current media/326 edition, current Iowa qualification law, or current skills-test administration. ↗
A dispatcher asks you to fill every available gallon of a cargo tank with liquid. What must determine the actual loading amount?
Correct answer: Required expansion space, the liquid’s weight, and applicable vehicle weight limits.
Liquids can expand in transit, so loading must allow the appropriate outage. Dense liquids can also reach weight limits before filling the tank’s volume.
Source: Iowa DOT official older Commercial Driver's License Manual, Hy-Brid Version October 2023 with July 2017 technical core; 8.2.6 Outage and 8.2.7 How Much to Load?; printed 8-2 (printed header displays 8-8-2), physical PDF page 104. Older technical guidance read 2026-10-01, not confirmation of the current media/326 edition, current Iowa qualification law, or current skills-test administration. ↗
