6 Causes Of Grinding Noise When Braking

Rusty Brake Rotors

Brakes are a critical part of a car. Without them, you cannot bring your vehicle to a stop, leading to serious accidents.

A moving car without brakes is a danger for the driver and passengers and pedestrians who might get in the way.

Therefore it is your duty as a car owner to keep your car’s brakes in good shape. The good thing about brakes is that they wear out gradually, and you can feel when they are about to fail.

6 Causes Of Grinding Noise When Braking

  1. Worn Brake Pads
  2. Stone between brake pad and rotor
  3. Rust on rotor disc
  4. Low quality brake pads
  5. Worn disc rotors
  6. You are braking too infrequently

These are some of the different reasons that could cause your brakes to make a grinding noise.

Here is a more detailed list of the 6 most common causes of grinding noise when braking.

Worn Brake Pads

Worn Brake Pad

Brake pads are one of these parts that wear out with time, no matter which car you have. A brake pad has a service life of about 15,000 to 40,000 miles, after which it must be replaced.

It does, of course, depend on your driving style. The more often you apply the brakes, the faster the brake pads deteriorate. But why the squeaking noise?

Well, it is caused by the brake pad when all material of the brake pad is worn out, and it is just the metal plate left. When metal collides with the metal disc rotor, there is an unpleasant squeaking noise, and you hear this when you apply the brakes.

Some brake pad models also have a wear warning plate. When there is 2-3mm left on the brake pad, the plate will get in contact with the disc rotor. This will cause a high pitch noise – so you know when it is time to replace the brake pads.

Stone between Brake Pad & Rotor

Stone In Brake Rotor

A widespread problem that happens with a lot of car models – even more in modern ones is that stones and other solid parts get stuck in the brakes between the brake pad and the disc rotor. It can also get stuck between the caliper bracket and the brake rotor.

The sounds of a stone between the brake pad the brake rotor is high and horrible.

If you experience this, you can try to reverse and forward with your car several times to see if it will get removed. Otherwise, you have to take the brakes apart to remove the stone.

Rust on Rotor Disc

Rusty Brake Rotor

Rust can form on any metallic component if water remains on them. When you wash a car, one of the difficult places to dry is your car’s brake system. The brake rotors of the braking system are made of metal and can succumb to rust.

As soon as this happens, the car starts making strange noises while the tires are running and when you try to brake.

If you are sure there are no other problems with your brake system, you can often solve this by going up to high speeds and braking hard a couple of times.

Low-Quality Brake Pads

Cheap Brake Pads

If you have your brake pads changed, you should never install cheap brake pads, as they can make squealing and grinding noises. If you know that you recently changed the brake pads – check what type of brake pads was installed.

If you tried to save some money and installed cheap brake pads – I have bad news, you probably have to buy new ones if you do not want to live with the braking noise.

I recommend buying brake pads from a well-known brand. Highly recommended are brake pads from Bosch; they are often not too expensive and very high quality. Make sure to choose the right brake pads for your car.

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Worn Disc Rotors

Removing Edge From Brake Rotor
Removing Edge from brake rotor

If you have worn disc rotors and haven’t replaced them in a while, there is a big risk that they are very worn.

Very worn brake rotors will create a deep outer edge of the rotor. This edge will cause a squealing noise when braking in most cases.

Luckily, you can often remove this edge by using an angle grinder. However, if the brake disc is too worn, you should replace it. Check the minimum thickness in your repair manual.

You are braking hard too infrequently

Braking Hard

Another common problem is that you are braking too little and not using the brakes to their full potential.

This will create rust on them and cause them not to move freely, which in return will cause them to start making grinding and squealing noise.

Try braking hard at higher speeds once in a while to heat them a little bit. This helps your brakes stay in good shape longer and will cause fewer frequent visits to the workshop.

Written by: Magnus Sellén

Founder, owner & main author of Mechanic Base. I have been repairing cars for more than 10 years, specialized in advanced diagnostics & troubleshooting. I have also been a drifting driver and mechanic for over 7 years.