When should I replace my brake pads?

All cars are equipped with disc brakes and brake pads. Brake pads are inserted into a brake caliper that grips the brake disc when the vehicle is moving to slow and stop the vehicle. A brake pad is a wearing part, as its lining loses material as it rubs against the disk. A good quality pad will provide good braking performance.

Why replace your brake pads?

The primary reason for replacing brake pads is pad wear. Friction during braking causes the pad lining to lose material. Don't wait until your pads are too worn to change them, or the metal backing they sit on could come into contact with the rotor and damage it, forcing you to replace your rotors as well. What's more, if your vehicle has to pass a roadworthiness test, replacing the brake pads beforehand will reduce the risk of a second inspection.

What happens when brake pads wear out?

To determine if your brakes are in good condition, you need to see, hear and feel them. This will give you a good idea of when to replace your brakes for a smoother, safer ride. Look for these signs to know when it is time to replace your brake pads or shoes:

Squealing or grinding noises

If a vehicle's brake pads have wear indicators, the driver may notice a grinding, squealing or whining noise when the brakes are applied. Brake squeal is normal under normal driving conditions, depending on the cleanliness of your brakes, the materials of your brake pads, and the weather conditions. However, squealing is a warning that your brake pads need to be replaced. Some brake pads have a semi-metallic layer embedded in the material or an external sensor designed to emit a screeching sound when the pad needs to be replaced. This shrill sound can be heard even without applying the brakes. If you wait too long at this stage, the screeching sound will be replaced by a squealing sound, which means that the pads are completely worn out and may cause additional costs due to damage to the brake disc.

When the brakes are exposed to wet conditions, such as after a rainstorm, the pads can make a very similar noise when braking. If the noise disappears after the first few brake applications, it is simply a little moisture on the pads or shoes and not a sign that they need to be replaced.

Less than a quarter-inch of pad wear

On disc brakes, you can also visually inspect your pads to see if it's time to replace them, although this may require removing the wheels. Looking at the brake assembly or "caliper" that contains the pads, you should see your pads compressed against the disc. If the friction material on the pad or shoe is less than ¼ inch (about seven millimeters) thick, consider having your brakes inspected, especially if it's been a while since your last inspection.

Low metallic squealing and growling

If you hear a low, deep noise that sounds like metal grinding or growling, it could be a sign that not only are your pads worn, but that your pads or shoes are making contact with the rotors or drums. Because this metal-to-metal contact can quickly cause further damage to your braking system, take your vehicle to a service center as soon as possible if you hear this type of noise.

Warning Lights

Some cars have a warning light on the dashboard to let you know when your brakes need to be replaced. Most sensors have the same life span as brake pads.

Car pulling to one side

If you feel your car pull to one side or the other while you're driving, your brake pads may be worn or the caliper guides or pistons may be sticking.

Vibration

If you feel vibrations when braking, your rotors may be abnormally worn or have suffered thermal damage from heavy braking.

When should you replace your brake pads?

Brake pad life depends on a number of factors, including

• How often the car is used and maintained: The more you drive your car, the more stress is put on the brakes;
• Driving style: if you use eco-driving techniques, you'll save on brake pads;
• The environment in which the vehicle is used: the condition of the roads you drive on also affects the use of parts related to the braking system.

As a general rule, you should replace your brake pads when:

• You have driven 30,000 km since the last replacement,
• The pad lining is 2 mm thick;
• The brake fluid level is at a minimum;
• The warning light (if you have one) appears on the dashboard;
• You notice signs of wear (abnormal noises, overheating of the brakes, etc.);

Change the brake pads. When you change your pads, you are not required to change your rotors. However, if you replace the rotors, you must also replace the pads.