Driving a Motor Vehicle with Failed Service Brakes During Downhill Descent
1 Answers
During downhill driving, failure of the service brakes refers to the malfunction of the foot brake. Engine braking can be used to decelerate the vehicle to a stop. In emergency situations, the vehicle can also be stopped by scraping against roadside obstacles to prevent more severe accidents. If the service brakes fail, the parking brake can be employed. However, it is advisable to primarily use engine braking during downhill descents. Parking brake braking involves using the handbrake to stop the vehicle, but it is not necessary to pull the handbrake to its maximum extent immediately; instead, gradually applying the handbrake can achieve appropriate deceleration. Below are relevant details: 1. Engine Braking: This involves lifting the accelerator pedal without depressing the clutch, utilizing the compression resistance, internal friction, and intake/exhaust resistance generated by the engine's compression stroke to create a braking effect on the drive wheels. Engine braking leverages the engine's drag effect to reduce speed, with lower gears providing more noticeable drag and stronger braking performance. 2. Downhill Driving Precautions: When driving on long downhill roads, engaging a lower gear and utilizing the engine's drag effect can reduce the burden on the brakes and minimize the frequency of braking, thereby preventing brake overheating and subsequent thermal fade. On snowy, icy, or muddy road surfaces, using engine drag braking can help prevent skidding.
