Brake Failure on a Downhill Gradient
You are driving a fully loaded 18-tonne lorry down a steep hill with a 10% gradient. The road is wet, and you are using engine braking and intermittent service braking to control your speed. Suddenly, you notice that the brake pedal feels spongy and the vehicle is not slowing as expected. You can smell burning. There is a lay-by about 200 metres ahead on the left. There is traffic behind you and oncoming traffic. Your speed is increasing.
1. What is happening, and what immediate actions should you take?
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The symptoms indicate brake fade, likely due to overheating from continuous use on the steep gradient. The spongy pedal and burning smell suggest the brakes are overheating and losing effectiveness. Immediate actions: 1) Stay calm and keep control. 2) Use engine braking by downshifting to a lower gear to help slow the vehicle. 3) Apply the brakes firmly but avoid pumping, as this can worsen fade. 4) Look for an escape route: the lay-by ahead could be used to stop safely. 5) Use hazard warning lights to alert other drivers. 6) If necessary, use the emergency handbrake gradually, but be careful not to lock the wheels. 7) Avoid sudden movements. 8) Once stopped, allow brakes to cool and seek assistance.
2. How could you have prevented this situation?
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Prevention: 1) Before descending a steep hill, select a low gear and use engine braking as the primary method of speed control, avoiding continuous service braking. 2) Check brakes before the descent and ensure they are in good condition. 3) Use intermittent braking rather than riding the brakes. 4) Be aware of the load weight and adjust driving accordingly. 5) On wet roads, allow more distance and reduce speed. 6) Consider using a retarder if available. 7) Plan the descent: if the hill is long, stop periodically to let brakes cool. 8) Regular maintenance and brake checks.