Brake fade on the Black River descent
It is 16:20 and you are driving a small van loaded with 400 kg of tiles down a steep, winding road through Black River Gorges. The road is wet from light rain. You are in fourth gear of a five-speed manual gearbox. On a long descent the van has crept from 40 km/h to 55 km/h even though you have been applying light, continuous brake pressure. The pedal now feels spongy and travels closer to the floor, and you can smell hot brakes. On your left the ground falls away steeply; on your right is a rock wall. A cyclist is 50 m ahead, and a signed lay-by is about 150 m ahead. There is no mobile signal at this point. The van's handbrake is mechanical and works on the rear wheels.
1. What should you do in the next 150 m?
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Act immediately. Select third gear to increase engine braking, then second if the van still accelerates, and apply firm, steady pressure to the footbrake rather than light continuous drag. Use the full width of your lane, keep left of the cyclist, and aim for the lay-by 150 m ahead. Switch on hazard lights and sound the horn briefly if the cyclist may be surprised. Do not ride the brakes continuously; that is what has overheated them. If speed cannot be controlled, use the rock wall side gently rather than the drop side, but only as a last resort. Stop in the lay-by, out of the traffic lane.
2. Why is coasting in neutral dangerous here, and why not rely on a hard handbrake application?
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Coasting in neutral removes engine braking, so the van's speed would rise on the descent and the already fading brakes would have to absorb all the energy. That makes fade worse. A hard handbrake application at speed can lock the rear wheels, cause a skid, or overload the rear brakes; the handbrake is for holding the vehicle once stopped or as a controlled emergency aid. Keep the gearbox engaged, use a low gear, and use the handbrake progressively only if the footbrake fails. Also avoid shutting off the engine, which would lose power assistance and possibly steering assistance.
3. After stopping in the lay-by, what should you check before deciding whether to continue?
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After stopping, let the brakes cool naturally; do not pour water on hot discs or drums, as they may crack or warp. Check brake fluid level and look for leaks around the wheels and master cylinder. Press the pedal: it should feel firm and hold pressure. Look at the wheels for smoke or excessive heat, and check the handbrake. If the pedal is still spongy, fluid is low, or a leak is found, do not continue; call for recovery, because there is no mobile signal and a failed brake system on the next descent would be catastrophic. If everything is firm and fluid is correct, drive slowly in low gear to the nearest garage for inspection.