Large Goods Vehicle (LGV) Theory Practice Test

Brake fade happens when the braking system overheats from prolonged use, which is common on long downhill gradients. To avoid this, you use engine braking by selecting a lower gear before or during the descent. This lets the engine help slow the lorry, keeping the service brakes cooler and preventing loss of braking effectiveness. By sharing the work with the engine, you can maintain a safe, controlled speed without continually riding the foot brakes.

Other options don’t address heat buildup in the brakes. Draining air tanks helps keep the air system dry and reliable, but it doesn’t prevent overheating of the brakes. Applying the parking brake before stopping doesn’t control speed on a downhill and can cause brake overheating or unexpected stops. Checking that the air pressure is correct is essential for brake function, but fade is mainly about heat, not insufficient air pressure. The key is using the appropriate gear to maximize engine braking on descent.