Revision question · Braking systems

On a vehicle with air-operated service brakes, which system may lose effectiveness from extra footbrake use while coasting downhill?

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

The air brakes

The cooling system

The tachograph

The electrical systems

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The air brakesThis was the right answer

Coasting removes engine braking, so the service brakes may have to do more work and lose effectiveness through repeated use. Stay in a suitable gear and use the fitted retarder as instructed. Merely selecting neutral does not itself stop an engine-driven compressor.

Reviewed reading for this question

Rule 122Highway Code rule · Coasting loses engine braking and increases service-brake demand; it does not simply switch off the air compressor.Save the service brakes on a long descentReviewed guidance summary · Coasting loses engine braking and increases service-brake demand; it does not simply switch off the air compressor.

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