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Brake discs and pads: What is the service life?

Brake pads, disc brakes, brake shoes, and drum brakes are wearing parts and wear out over time. Brake discs are also exposed to high mechanical and thermal loads. For this reason, the brake system should be checked for function and wear condition at every workshop visit.

It is recommended that the brake system be checked by a specialist when the wheels are changed, for example.

How long brake discs and brake pads actually last in practice depends entirely on the respective models. Some model series, for example, are known to rust prematurely.

  • The load on the brakes is usually different between the front and rear axles, so not all four wheels necessarily need repair.
  • Brake discs have a comparatively long service life. High-quality brake discs often last between 62 000 and 93 000 miles. Inferior products may need to be replaced after just 31 000 miles.
  • You usually have to change the significantly cheaper brake pads more frequently. The pads often last only 19 000 to 37 000 miles.

Causes of brake disc and brake pad wear

In most cases, wear is detected at an early stage when tires are changed in the workshop. Modern cars also display wear in the cockpit.

  • A change is necessary for disc brakes from a residual lining of 2 millimeters. For drum brakes, the brake lining should not be thinner than 1 millimeter.
  • If the noise persists or if the car pulls slightly to one side, you should definitely visit a workshop. If the components are worn, you will hear grinding. Another sign may be a slight shaking of the steering wheel or brake pedal.
  • One of the most common causes of brake discs and pads dying is rust. This occurs when you have not moved the car for a long time. Flash rust can form within just a few days if moisture gets between the brake disc and the brake pad.
  • The brake disc can also easily warp due to overheating or because of a bent wheel hub. Excessive wear of the brake pads can cause the brake to stick to the brake disc. If this is the case, you can feel the heat on the affected tire several centimeters away after a not too short drive.

How often do brake pads need to be replaced?

Recognizing worn brake pads

A persistent rubbing or grinding noise can indicate a worn component. If the vehicle pulls slightly to one side or there is slight shaking of the steering wheel or brake pedal, these are also harbingers of wear.

Other indications of worn or defective components are a fluttering or pulsating brake pedal, a low level of brake fluid, or a longer braking distance. If you are unsure, you should not take any risks here and, if in doubt, ask a specialist for advice.

Extending the service life of brake discs and brake pads

Ultimately, the service life depends not only on the components but also on your driving style.

  • If your brake quickly rather than slowly, this can increase the wear of the brake pads in the long term. However, with an average driving style, this should not be the deciding factor.
  • One of the biggest enemies of brake discs and pads is rust. If light flash rust has formed on the brake disc, you can brake it away relatively easily.
  • To do this, accelerate to 162 mph on the freeway exit ramp or on an empty country road and brake a little harder than usual, but do not perform an emergency stop. Due to the heavy braking, light rust will dissolve by the third attempt at the latest.

Brake service: duration

The cost of brake service depends primarily on the worn parts to be replaced. If only the front brake pads need to be replaced, this is naturally cheaper than the replacement including brake discs. The size of the brake discs and pads also plays a role. In terms of working time, about 20 to 30 minutes per wheel should be calculated for pad replacement.

As a rule, brake pads are replaced axle by axle. Many workshops offer the replacement of brake pads at a complete price. If the discs also have to be changed, the price can double or even triple. This is because the cost of brake discs is significantly higher, while the additional work time is kept within reasonable limits (about 15 minutes per wheel).

What happens when brake pads wear out?

Negative side effects

On brake discs and drums, there are embossed indications of the permissible minimum thickness or maximum diameter. As a rule, two to three millimeters of wear are permissible before these parts have to be replaced.

Important: As the brake wears, the level of brake fluid in the reservoir also drops.

Nevertheless, you should not top it up until it has reached the minimum level. Otherwise, the reservoir will overflow when the workshop installs new pads and sets all brake pistons to the beginning.

Problematic: Regardless of the degree of wear of the brake components, unpleasant side effects can occur during deceleration.

These include rubbing, i.e. when the brake grips with varying force over a wheel revolution. The rubbing can often also be felt in the steering wheel or even in the brake pedal and is not only annoying but also damaging to the entire wheel suspension. The causes can vary, ranging from rust on the brake disc after prolonged parking in the rain to distortion due to overheating or as a side effect of a bent wheel hub

FAQ

How do I know when my brake pads need changing?

Squeaking or squealing coming from brakes. Grinding sound when braking. Vibration when braking. Taking longer to stop. Brake pad indicator light comes on. Your brake pads appear to be thin.

What happens when brake pads wear out?

If you start to hear your brakes squeal and act up and you ignore the issue, they can still work for a while, at least somewhat, even if they don’t stop your car as fast. But the longer you wait, the more damage they can do.

David Muench (Carnes Mechanical)

David Muench (Carnes Mechanical)

Hey, I’m David. I’ve worked in a cars store for 6 years. I write reviews and guides, helping people to choose the most suitable technicals and best product for them. I’m happy to finally share my knowledge of the industry here, on CarnesMechanical.

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