Revision question · Braking systems

You're about to drive an unfamiliar vehicle. What should you do if you think there may be moisture in the air-brake reservoir?

Revision material from the imported DVSA bank includes source-checked Lanekind learning corrections. These corrections are not newly issued official examination questions, and practice does not reproduce a live test paper.

Answer options

Assume the system has automatic drain valves

Find out whether you need to drain the system manually

Nothing; it's the vehicle owner's responsibility

Leave the engine running for a while before driving

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Find out whether you need to drain the system manuallyThis was the right answer

Moisture in the braking system can cause serious problems, especially in cold weather, when it could freeze and stop the brakes from working. Most modern vehicles have a system that drains automatically, but make sure you know which system is fitted to any vehicle that you drive.

Reviewed reading for this question

Match reservoir draining to the fitted air systemReviewed guidance summary · The corrected manual-drain question names the no-dryer system; unfamiliar vehicles require checking, and frozen reservoir moisture can impair pressure build-up.

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