Torque Shop: Special brake fluid to tackle a hilly road trip

My motor mechanic has advised me to switch to high-temperature brake fluid and fit high-temperature brake pads in preparation for my driving holiday to Cameron Highlands. What is all that about?

This is good advice from your workshop. Driving down Cameron Highlands requires frequent braking to cope with the multitude of sharp curves. Also, higher braking pedal pressure is needed to manage the steep descents.

Such driving conditions have two crucial and inevitable results: brake pads heat up faster than normal with very little time to cool down, and the heat from the brake calliper will be transferred to the brake fluid.

Brake pads are designed to work properly over a wide range of temperatures. However, at temperatures that are beyond their design limits, their effectiveness fades.

High-temperature performance-oriented brake pads are made to perform well in hotter conditions. However, such brake pads also require higher temperatures for optimum performance. This simply means that they are not at their best during gentle driving because the pads remain relatively cool.

When the brake fluid temperature gets to the point that it starts to boil, the liquid begins to convert into a gaseous state. It loses compressibility and the brake pedal will begin to feel soft and become ineffective in slowing down the car. The hydraulic brake system in any motor vehicle functions on the principle of incompressibility in liquids.

Both the conditions described above contribute to what is called “brake fade”.

While performance brake pads and high-temperature brake fluid will help the driver avoid such dangerous circumstances, the more important driving advice for descending long and winding hills is to use the brake pedal sparingly, reduce speed and shift to lower gears to rely on engine braking as far as possible.