Hello Paul, where I live, we often have to drive on winding or hilly roads. When I drive fast downhill, I notice a burning smell and reduced braking power. Does frequent high-speed driving damage the braking system or gearbox? What is the best way to control speed without overworking my car, especially on steep slopes?
Sula
Hello Sula, frequent high-speed driving downhill on winding roads can cause burning of brakes when you apply them suddenly or constantly (riding brakes). This usually happens because the vehicle load and momentum tend to increase as you drive faster downhill. Also, directional road forces are severely at play as you manoeuvre the vehicle around sharp corners of the winding road. This causes more stress and heat from increased friction when you apply the brakes. This results in brake pad accelerated wear, hence the burning smell.
You tend to experience reduced braking force as the brake fluid overheats and reduces vital hydraulic pressure in the brake system. In equal measure, high-speed driving downhill can stress your automatic gearbox internal components, such as the torque converter, more because the increased load of the car caused by increasing momentum and downward forces. This will be worsened when you apply the brakes hard and the gearbox has to downshift suddenly.
A manual gearbox system also suffers some level of stress if the driver is not skilled enough to downshift carefully. Components such as the clutch friction disc and pressure plate will wear out prematurely. You can control the speed when driving downhill in a manner that prevents stressing your car. Apply the brakes gently and gradually, rather than jamming them suddenly. This helps you reduce or control the speed of the car without stopping its movement.
This does not mean unnecessary riding of the brakes or constantly keeping your foot on the brake pedal. This works well if you can keep monitoring the speedometer to know how fast the vehicle is moving downhill. This knowledge guides your braking style and use of the gears or transmission. Engine braking is a useful way of reducing frictional wear or mechanical stress occasioned to the brakes and transmission during downhill driving. To use engine braking, you release the throttle, gently downshift to lower gear three or, in extremely low slopes, gear two for manual transmission.
The automatic gearbox will downshift as soon as you release the throttle. The engine and transmission will take over to slow the car as gears shift down. Use of engine braking not only saves your brakes from wear but also increases your road safety as it improves control of the vehicle on the sloping and winding roads. Sudden braking when driving downhill can cause skidding and loss of control.
On the maintenance side, you need to make sure your brake pads and shoes are in top-notch condition before you drive up and down hilly roads. Your car's brake fluid should be serviced and at the correct level. Good and correct quality brake fluid helps to build brake pressure when you need it, cools the hot brake system and drives away harmful corrosion from critical brake pistons. All these features are critical for brake performance and your safety.
