When should brake pads be replaced?

Brake pads wear out, and they warn you before they are finished. Catch the signs early and you only replace the pads; leave it too late and the discs go too, doubling the cost.

Signs that your brake pads are worn

1. A thin, high-pitched squeal when braking. Many pads have a small metal wear indicator that rubs against the disc when the pad gets thin.
2. Metal-on-metal grinding. The pad is completely gone and the steel backing plate is touching the disc. Do not drive the car like this.
3. A brake warning light on the dashboard. On cars with wear sensors, the light comes on when the pad reaches its limit. The sensor is usually replaced together with the pads.
4. Vibration in the steering wheel or pedal when braking. This usually means the disc surface is damaged.
5. The car pulls to one side when braking. A caliper may be sticking, or the pads may have worn unevenly.
6. The pedal travels further than it used to. The fluid level may have dropped; the level in the reservoir also falls slightly as the pads wear.

How to check them by eye

Looking through the wheel spokes at the caliper, you can see the friction material of the pad. If it is down to about 3 mm, it is time to replace them. To be sure, you need to take the wheel off.

A value such as "MIN TH" or "MIN 22 mm" is stamped on the edge or hub of the disc. This is the minimum thickness the disc may wear to. If your caliper reading is close to it, or the disc has deep grooves or a pronounced lip at the edge, the disc must be replaced as well. New pads do not bed properly on a damaged disc and wear out early.

Choosing the right pads

Pad sizes can differ between model years of the same car, and even between engines in the same year. Front and rear pads are different too. That is why the safest way is to select your car by make, model, year and engine and look only at matching parts on the brake systems page. Compare the code on your old pads as well; we explain how in the What is an OEM part number and how do you find it? guide.

Replacement pads and discs sold in Europe should carry ECE R90 approval. Seeing this mark on the box shows the product has been tested.

What to do after replacing them

• Pump the pedal several times before driving off. Because the pistons were pushed back, the pedal goes to the floor on the first press. Driving off without doing this is very dangerous.
• Check the fluid reservoir. Pushing the pistons back raises the level; make sure it does not overflow.
• Bed the pads in. Avoid sudden, hard braking for the first few hundred kilometres and let the pads settle against the discs.

FAQ

How many kilometres do brake pads last?

It depends heavily on use. Cars that brake often in city traffic wear them faster; check the thickness rather than relying on a fixed mileage.

Should the discs be replaced with the pads?

If the disc is above its minimum thickness and the surface is smooth, it does not need replacing. If the discs are replaced, the pads must always be renewed too.

This guide gives general information. Torque values, fluid quantities and service intervals vary by vehicle; follow your owner's manual. If you are unsure about safety-related work, ask a mechanic.