Brake fade is a term used to describe the deterioration in the ability of brakes to slow the car. You will know that your car is suffering because you have to press the brake pedal progressively harder to get the car to slow down.

There are three types of fade. The most common happens with new brake pads, an effect called green fade. Brake pads are a complex mix of fillers, lubricants, fibres and a binder resin that holds the whole lot together. Because some of the contents are organic they will, under intense heat, turn to gas. If the brakes are used too hard before they are fully cured enough gas can be produced to act as a cushion between the pad and the disc, reducing friction substantially.

Most modern pads come pre-baked in order to try to remove the potential for this gas build-up, but gentle use of new pads in the first 100 miles or so is the best way to ensure the pads are fully cured.

Overheating of the pads through hard use also produces the second type of fade. When too hot, the resin can melt and act like a lubricant between pads and disc. As with green fade, the pedal action doesn’t become any spongier — it feels as firm as always, but the braking effect is considerably reduced.

The third form of brake fade is fluid fade. When this happens the brake pedal does become spongy, and sometimes you can push the pedal to the floor with little effect. It is caused by boiling brake fluid.

Brake fluid is hydroscopic, meaning it absorbs water from the air very easily. The more it absorbs, the further its boiling point drops, until it falls low enough to be boiled by heat from the brake. This creates gas bubbles in the brake lines and pressing the pedal simply compresses the gas without applying the brakes.

The cure is to change the brake fluid, using a replacement only from a sealed tin. Even an hour’s exposure to humid air is too much.

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