When you hit the brakes, you don’t want to hear a grinding noise. You may even find it more concerning than the typical squeaking that occurs when the pads are worn.
The noise can get loud enough that other people driving next to you begin to give you funny looks. So, what causes a grinding noise from the brakes and how do we fix it?
In this article, I go through all possible explanations of why the brakes are grinding as well as how to fix the grinding brakes for increased safety and less noise.
At the end of the article, your top brake questions will finally be answered to help learn if you are safe if your brakes are grinding.
Causes Of Grinding Noise When Braking
Worn brake pads or damaged rotors often cause brake grinding noise. If you have broken brake pad shims or low-quality pads, or if you haven’t driven your car in a while, grinding can occur as well. With a thorough inspection, you’ll know how to proceed without worrying too much about the grinding in your brakes.
Below we outline the most common incidents causing grinding noise from the brakes when you apply them.
#1. Worn Brake Pads.
Once the brake pads have worn and get close to the metal backing, you are going to start hearing a grinding noise. Brake pads can be made from steel, graphite, brass, or copper. When this material wears off, the metal backing gets uncovered, which creates the grinding noise.
You get warning before this occurs. When the brakes go bad initially, they are going to create a squeaking or squealing sound. If you replace them before it gets to the grinding stage, you may never hear the grind.
Depending on the type of brake pads you choose, they can last from anywhere between 25,000 to 60,000 miles.
#2. Stone Stuck Between Rotor And Caliper.
Grinding or screeching noises may indicate something more than possible bad brake pads, especially if the noise occurs with no brake action. One possibility is a small piece of debris, like a stone, may be caught in the caliper. If debris is left unresolved, it can damage the disc brakes.
Sometimes, the stuck item falls out when the car is moved. If not, the item can be moved forward and backward to see if it comes out.
#3. Broken Brake Pad Shims Against Rotor.
Broken brake shims can also make a grinding sound. Worn shims can contact other parts of the brake system, usually the rotor. When one metal surface touches another metal surface, it can create a grinding sound.
That’s why new shims are installed when replacing the brakes, and if they get missed, then you may run into problems.
#4. Rusty or Worn Brake Rotor.
Brake rotors are flat metal disks that slow a car down when the calipers squeeze the pads together. Over time, water and dirt work their way into the rotor and cause warping or rusting.
When the rotors are worn, you might hear grinding, the rotor can be resurfaced, but usually, the rotors will need to be replaced. The good news is that rotors generally last longer than the brake pads. Overall, you can expect around 50,000 – 70,000 miles out of a set of rotors.
#5. Low-Quality Brake Pads.
While it is understandable that you want to save money when the opportunity arises to buy new brake pads, you could be causing your own undoing by trying to save money in the first place. If you have low-quality pads, you could find yourself with more noise than you wanted.
Cheap pads are higher in metal content than performance brakes, making them more susceptible to scraping or grinding. Organic brake pads have the lowest price point and are also the lowest quality.
To make these, a mixture of fiberglass, fibers and Kevlar with resin can be used. Semi-metallic brakes are a step up with better durability and less noise. The best pads however are ceramic, although you will pay for this quality.
#6. You Haven’t Driven Your Car In A While.
You might wonder why your car’s brakes would grind if you don’t drive your car often. After all, you haven’t driven it much so you wouldn’t have worn down the pads. The problem could actually arise from sitting still, which will cause rust.
The noise you are hearing from the brake system will be only the beginning of your problems after having it sit. You could have fluids leaking, flat spots on the tires, and a dead battery. You could face a long list of issues and that is why you should drive the vehicle at least once per week.
How To Fix A Grinding Noise When Braking?
No matter your experience level, you can still assess what’s wrong with the brakes when they start to grind, and I have a few simple steps for you to follow. But only do what you feel comfortable doing.
So, the five steps to consider are,
#1. Determine Which Wheel It’s Coming From.
Finding the source of the noise will provide the most insight into the problem. If you can identify which of the wheels it is coming from, that will make it easier to identify the issue.
If you can’t tell where the noise is coming from, ask a buddy to help. Have them stand outside while you brake in the driveway.
#2. Remove Wheel and Brake Caliper.
Now that you have identified where the noise is coming from, you now have a place to begin your investigation. Remove the wheel and brake caliper for a closer look.
You may even get a visible sign by pulling the wheel itself. However, I would recommend that you go even deeper in order to see the bigger picture.
#3. Inspect Brake Pads And Rotor.
With the brakes visible, you’ll have a better sense of what you need to repair. First, look at the brake pads and measure the thickness of them. New brake pads will be 3/8 to 1/2-inch thick.
Once the pad is down to 1/4-inch, it will be time to replace them. However, you probably won’t hear grinding noises until the pad gets down to 1/8-inch or 20 to 25% of the original thickness.
Rotor inspection will be a little different since you won’t look for how much thickness remains, but how the surface looks. The rotor face should be smooth and without imperfections.
Once there are signs of warpage or damage done to the metal surface, it will be time to resurface them or replace them. Brake pads and rotors should be changed in pairs.
#4. Look For Stuck Stones Or Broken Shims.
Small stones or debris usually won’t damage the rotor. They will typically work their way out of the brakes through normal use if you can ignore the sound. If you can’t ignore the sound, or you’re afraid the stones are larger, you’ll want to remove them.
Brake pads have shims to stop the noise. While these should be replaced with the new pads, they can be forgotten. So a quick inspection of the pads is a good idea if your new brakes are noisy.
#5. Contact A Professional.
If you’re unsure about the brake system, don’t go looking for trouble, as it’s best to leave this type of work to trained professionals.
You may also find that you are fairly certain you can start the investigation and repair activity with confidence you can address the noise. After getting started, you realize you are in deeper than you anticipated.
At this point, there is nothing wrong with reaching out for assistance or help to resolve the issue. Better to solve the brake issue correctly instead of becoming a bigger problem later.
Is It Safe To Drive If My Brakes Are Grinding?
If your brakes make unusual sounds, you should have them checked immediately. The brakes can fail at any point and leave you in a dangerous situation. The cost of replacing the brake pads, rotors, and parts isn’t worth taking that risk on the road.
How Much Does It Cost To Fix Grinding Brakes?
Typically, you can expect to pay about $150 each axle to replace the brake pads. If you need the rotors replaced, that cost is about $200 each axle. And, if there’s something in the brakes, you may need additional service, and you may save yourself some money if you do this work.
How Long Can I Drive On Grinding Brakes?
You should not drive with the grinding brakes. When your pads started wearing, you typically had a warning sign through noise with squeaking and squealing. Now that there is metal to metal contact, this is dangerous. Or, something needs immediate service.
Will Replacing Brake Pads Stop Grinding?
If the noise of grinding true to worn brake pads, then the only option is to replace the pads.
However, if you replaced the pads and still hear the grinding noise, then you will likely need rotor replacement as well. This is also why it is best practice to have it checked out prior to you approved a repair.
What Happens If You Don’t Fix Grinding Brakes?
If the brake pads or rotors are bad, you could be without brakes when you need them most. The grinding is a warning that there is something majorly catastrophically wrong with the braking system and it requires your attention. If you fail to fix it, you risk damaging the important brake components.
If you hear a noise that sounds like grinding when braking, you should always treat it seriously. This noise is trying to tell you there is a danger lurking.
Whether you need to put new brake pads on, resurface the rotors, or pull something out of the system, it is better to take care of the problem as soon as possible or you may find yourself in a very bad position when the brakes fail.
Most of the time, diagnosing an issue with the brakes and fixing them is easy, however, having the proper tools and some experience typically makes the job easier too. Sometimes, you could get away with performing some of the jobs in your home garage.
Home mechanics enjoy the challenge of putting a new set of brake pads on a car. There is nothing wrong with getting a little extra help if the job is more than you can handle. After all, the main thing is to keep everyone safe on the roads.