When to Replace Brake Pads (Minimum Brake Pad Thickness)
Brake discs are the modern version of the brake shoes used in the old drum brake systems. Today, most vehicles use disc brake systems to help drivers slow and stop their vehicles.
The system consists of brake calipers that contain pistons and brake pads. There are also rotating discs that rotate with the wheels as the vehicle moves. The brake calipers apply pressure to the brake pads, forcing them against the brake discs. Friction between the brake pads and the brake discs slows down the rotation of the wheels. This happens every time the driver presses the brake pedal.
The materials used to make brake pads include steel backing plates, washers, friction materials, rubber coatings, and thermal insulation coatings. Although these are strong materials, they are not tough enough to last forever.
Eventually, your brake pads will need to be replaced. Brake pads are used every time you press the brake pedal, so they wear out after about 50,000 kilometers.
However, you can extend the life of your brake pads by using brake pads of the appropriate thickness. Below, we will explain the thickness levels.
Minimum thickness of brake pads
When the brake pads rub against the disc, the friction material wears out. When measuring the thickness of the brake pads, we measure the thickness of that material. If the friction material is too thin, it will not be able to slow the vehicle down quickly after you press the brake pedal. If the material melts completely, the brakes will eventually fail.
The minimum brake pad thickness recommended by the manufacturer must be adhered to. In most cases, brake pads should be replaced when they are worn down to around 3mm. Sometimes they can be as thin as 2mm, which exposes the metal wear indicator and causes a squealing noise against the disc. Please note that thinner pads have less heat resistance and a higher risk of cracking. Therefore, a thickness of 3-4mm is often recommended for brake pad replacement.
It may be okay to make the thickness a little thinner, but be sure to keep it at least 2mm. At this point, braking performance will decrease and the brake rotor will be more likely to be damaged.
Recommended brake pad thickness
When purchasing new brake pads, you should make sure that the friction material is about 10-12 millimeters thick. This is the standard thickness found on most new brake pads.
It takes about 50,000 miles (with some variation) for the thickness to drop to 3-4 millimeters. It all depends on how aggressively and frequently you use your brakes. So, for many people, 50,000 miles is the average, but for others, 20,000 miles is more realistic. Also, keep in mind that some brake pad materials last longer than others.
You can buy new brake pads at your local auto parts store or online, but the best way to get the right brake pads is to have them replaced at the dealership where you bought your vehicle. How to check brake pad thickness
1. Brake pad gauge (like this one or this one)
2. Wheel nut wrench (like this one)
3. Jack and jack stands (if needed)
Steps:
1) Park the vehicle on a level surface and wait for the engine to cool. For safety, apply the parking brake.
2) Loosen the lug nuts or bolts on the wheel you want to inspect and raise the vehicle with the jack. Place jack stands under designated lifting points for stability (see owner’s manual). Remove the wheels to gain easier access to the brake assembly.
3) Find the brake caliper, which is the large clamp-like device that houses the brake pads and pistons.
4) Inspect the brake pads without removing them from the caliper. Look at the outer edge of the pads and you should be able to see the friction material there.
5) Use a brake pad gauge to measure the thickness of the friction material. Place the gauge on the base and record the reading.
6) Compare the measurement to the manufacturer’s recommended minimum thickness (usually 3-4mm). When the brake pads reach or fall below this thickness, it’s time to replace them.
7) Repeat the measuring process for the inner brake pads (each wheel has two brake pads).
8) Reinstall the wheels and torque the lug nuts to the manufacturer’s recommended torque.
9) Repeat this process for each wheel.
Factors that affect brake pad wear
Understanding these factors can actually help you extend the life of your brake pads and better plan for brake pad replacement costs.
1. Driving Habits: Driving style plays a major role in brake pad wear. Frequent hard braking, riding your brakes, and rapid acceleration with abrupt stops put more stress on the brake pads, causing them to wear out faster. Smooth, gradual braking, maintaining a safe following distance, and not driving with your foot resting on the brake pedal can help reduce brake pad wear.
2. Vehicle Type and Weight: Heavier vehicles, such as SUVs and trucks, require more braking force to stop, which can lead to faster brake pad wear compared to lighter passenger cars. Additionally, high-performance vehicles with powerful braking systems may experience more rapid brake pad wear due to the increased friction and heat generated during braking.
3. Environmental Conditions: Driving in dusty, muddy, or sandy environments can accelerate brake pad wear. Abrasive particles can become embedded in the brake pads, causing them to wear down more quickly. Exposure to salt in coastal areas or on winter roads can also contribute to faster brake pad deterioration.
4. Brake Pad Material: The quality and composition of the brake pad materials can significantly impact their lifespan. Higher-quality brake pads made from advanced materials, such as ceramic or high-performance composites, often last longer than lower-quality, budget-friendly options.
5. Driving Terrain: Frequent driving in mountainous or hilly areas that require constant braking can lead to faster brake pad wear compared to driving on flat, straight roads. The increased use of brakes to control speed on descents puts additional strain on the brake pads.
6. Vehicle Maintenance: Proper vehicle maintenance, including regular brake system inspections and servicing, can help identify potential issues that may contribute to premature brake pad wear. Factors such as misaligned wheels, stuck brake calipers, or worn suspension components can cause uneven or accelerated brake pad wear.
7. Towing: Vehicles that frequently tow heavy trailers or haul substantial loads put extra stress on the braking system (especially in hilly areas), leading to increased brake pad wear. The added weight requires more braking force, which can cause the brake pads to wear out more quickly and even overheat.
