What can coasting downhill seriously affect?

Explanation: Air-brake systems rely on an engine-driven compressor to keep the reservoir tanks at their operating pressure. Coasting downhill and relying on the brakes to control your speed could result in the loss of sufficient air pressure to operate the brakes effectively.

Category: Braking Systems

References: The Official DVSA Guide to Driving Buses and Coaches: Section 2, The Official DVSA Guide to Driving Goods Vehicles: Section 2