10 Causes of Grinding Sounds When Braking at Low Speeds

Close up of a disc brake rotor with scratches and groove marks visible creating grinding noise

The braking system is one of the most important components in a vehicle. When there is any kind of problem with your brakes, it’s crucial to understand what exactly is going on to ensure your safety on the road. One of the most common braking issues is a grinding sound while braking at low speeds.

Generally, a grinding sound while braking at low speeds signifies an issue with your brake pads. However, it could also denote a problem with your rotors, debris, or lubrication. In other instances, the sound could be a result of your vehicle sitting too long or the anti-lock braking system kicking in.

Below, we’ll discuss nine common causes of grinding sounds while braking at low speeds. Keep reading to learn more before you visit a mechanic!

10 Causes of Grinding Sounds When Braking at Low Speeds

It can be stressful to hear a grinding sound when you press your vehicle’s brake pedal. This may be happening for any number of reasons, some of which are definitely more cause for concern than others. Below, we’ll highlight nine reasons you may be hearing grinding noises when you’re braking at low speeds.

1. Worn-Out Brake Pads

The most common reason people hear a grinding sound when braking at low speeds is due to worn-out brake pads. Brake pads should typically last at least 20,000-30,000 miles, but certain driving behaviors can reduce their lifespan. Some of these include:

  • Sudden braking
  • High vehicle weight
  • Driving in heavily congested areas

Although these factors will cause your brake pads to wear out sooner than expected, even the most gentle drivers will need their pads replaced regularly.

Brake pads are typically made out of a combination of graphite, copper, and iron. With regular use over time, the metal surface eventually becomes exposed and starts making contact with the metal rotor surface. This often causes a grinding sound when you press the petal.

If you’re hearing this sound when braking at low speeds, the first thing you should do is have a mechanic check your brake pads. If they are worn down, replace them as soon as possible to ensure your safety on the road and prevent further damage to your vehicle.

Close up comparison between a new and old worn out brake pad for a car

2. Low-Quality Brake Pads

As mentioned above, high-quality brake pads usually consist of a combination of metals. These materials need to be distributed at a very specific ratio to ensure performance and longevity. In most cases, companies that offer cheaper, lower-quality brake pads do not have the equipment necessary to maintain these ratios.

Cheaper brake pads often contain large chunks of metal, which can quickly begin to rub and scrape on the surface of your rotors. In addition to a grinding sound, these can also cause serious damage to your brake rotors.

While not everyone has several hundred dollars to spend on car parts at any given time, brake pads are something you don’t want to cut corners on. High-quality brake pads from a reputable manufacturer may be more expensive upfront, but they’ll save you the headache of replacing your brake pads often. Plus, they may even prevent bigger, more expensive repairs in the future.

Set of four brake pads brand new isolated against a white background

3. Worn-Out Rotors

Like brake pads, a vehicle’s rotors will need to be replaced regularly to ensure proper operation. While a few scratches are normal, rotors can develop cracks, ridges, or even warping over time. This creates uneven wear, producing vibrations in the brake pedal and grinding sounds when stopping. It may also cause your rotors to rub around the wheel hub, leading to even more noise.

If your brake pads aren’t the issue here, the rotors are the next place to look. Like brake pads, you should always use high-quality rotors in your vehicle to ensure longevity. Replace both parts regularly to avoid problems.

Heavily worn out disk brake rotor needing to be replaced

4. Debris Between Your Rotors and Brake Pads

Another common cause of grinding sounds in your braking system is a build-up of debris between the rotors and brake pads. This is especially common if you live in an area with a lot of dirt or gravel roads.

While a little bit of sand, rocks, or pebbles between your rotors and pads are nothing to worry about, it can build up to the point where it creates a grinding sound. You’ll usually hear this while pressing the brake pedal, but at a certain level of build-up, you may even hear it as you’re driving along the road.

Although this build-up usually consists of sand, pebbles, or other road debris, it can sometimes include brake dust or very fine metal shavings. It’s a good idea to have the area cleaned out by a professional mechanic to see what exactly the debris consists of.

Close up of a brake disk rotor with metal shave groove marks visible from debris and the brake pads

5. Debris Between Your Rotors and Calipers

While debris between the brake pads and rotors is most common, debris can also get stuck between your rotors and calipers. As you drive, your car can kick up small rocks and other solid debris from the road. If this debris lodges between your rotors and calipers, you’ll usually hear a grinding noise.

Like getting debris stuck between the pads and rotors, this noise will be most noticeable when you’re braking at low speeds. But, you may even be able to hear it when the brake pedal is not engaged.

This is a much more severe issue than having debris between your pads and rotors, as it can lead to more serious damage over time. Have a mechanic clear this area of debris as soon as possible to avoid more costly repairs in the future.

Close up of a car brake disk rotor with the caliper highlighted in red

6. Dried-Up Caliper Screws

Most parts of your vehicle require proper lubrication to function correctly. One of these parts is your brake caliper screws. If the lubrication has worn off, or if they were not lubricated properly during installation, you may hear a grinding or scraping sound while braking.

Lubricating a caliper screw is not a difficult undertaking if you have some level of understanding regarding vehicle mechanics. However, if you don’t know what to look for, it’s best to consult a professional. Dried-up caliper screws are rare, but if nothing else seems to be wrong, it’s worth looking into.

Brake caliper close up with the location of the bolts highlighted in red

7. Unlubricated Brake Pads

As mentioned above, there are many parts of your vehicle that require constant lubrication to function properly. Brake pads are another one of these parts.

When your brake pads are first installed, the mechanic should use brake caliper lube to lubricate the back of the pads. If they neglected to do so, or if it was not done properly, the pads and caliper pistons can begin to rub against each other, creating a grinding noise.

This is typically an easy fix. If your brake pads are still in decent condition, a mechanic can add the proper amount of lubrication and then reinstall the same parts. Make sure to ask your technician to lubricate the caliper slider pins, which connect the two sides of the brake calipers, as well during this time.

Auto mechanic holding a new brake pad at the car service close up before lubricating it and installing it on the rotors

8. Your Vehicle Was Parked for Too Long

While most people believe that driving their vehicles too often will lead to increased wear and tear, not driving your car for long periods can actually do just as much, if not more, damage. Leaving your vehicle parked for too long can encourage the braking system to catch a lot of air and vapors, eventually leading to rust and corrosion in the brake pads. 

This is especially true if you leave your car parked outside. Here, it’s exposed to extreme temperatures, precipitation, and wildlife, all of which can take a toll on your brake pads’ lifespans. Parking in a covered area, such as a garage or carport, will mitigate these issues, but long periods of inactivity are never ideal.

Once you begin driving your vehicle regularly again, the problem will likely go away on its own. However, leaving your car sitting for too long can still drastically reduce the lifespan of your brake pads. Remember to drive your car at least once a week, even if it’s just a trip down the road, to keep the brake pads in good condition.

Close up of rust formed on the disk brake after the vehicle was stationary for two weeks at home
Close-up of a brake disk rotor after being parked for just a few weeks.

9. Your Anti-Lock Braking System

A grinding sound while braking at low speeds typically signifies some kind of issue with your braking system. However, you might also hear it when your anti-lock braking system (ABS) kicks in.

Whether you’re driving at 70 miles per hour on the highway or 25 miles per hour down a residential neighborhood, there are some occasions when you have to slam on your brakes unexpectedly. When this happens, you may hear a grinding noise and feel your brake pedal rumble. When this happens, it means your ABS has automatically activated.

The ABS prevents wheel lock-ups and skids when you brake suddenly. It works by automatically pumping the brakes, which ensures you maintain control and stability over your vehicle. Once you take your foot off the brake, the grinding should stop. If you’re only hearing a grinding sound when you brake suddenly, it’s likely just the ABS in action, which is not a cause for concern.

Close up of an ABS control unit for braking assist
ABS Control Unit

10. Backing Plate (Brake Plate)

The last thing I want to mention is the backing plate otherwise known as a brake plate. It essentially works like a splash guard and protects your braking components located on the wheels from debris and dirt.

However, because it acts as a protectant, it’s the first to corrode and rust. Because of this, and depending on whether or not your vehicle is driven on salt roads, the backing plate can warp. If there is even a slight warp, it can start grinding with the rotor metal to metal.

Close up of the brake rotor disk with the back brake plate visible highlighted in red

How Much Will It Cost to Repair This Problem?

The amount of money you’ll have to pay to repair a grinding noise within your braking system depends on which problem you’re dealing with. In general, there are four categories the above problems will fall under:

  • Brake pads
  • Brake rotors
  • Brake cleaning
  • Brake lubrication

Now, let’s discuss the average cost of repairing each problem.

Brake Pads

New brake pads usually cost between $115 and $300 per axle, depending on where you go and the quality you choose. As we’ve discussed, you don’t want to cut corners when it comes to brake pads, so going with a slightly more expensive option may pay off in the long run.

One important thing to remember is that the front brakes are responsible for approximately 70% of your vehicle’s braking abilities. For this reason, the pads in the back are smaller than those in the front, so they wear out pretty evenly. However, if you’re in a pinch, it’s better to focus on the front brakes first.

Set of brand new car disk brake pads in a green box ready to install

Brake Rotors

New rotors are a bit more expensive than new pads, usually falling between $250 and $500 per axle. Like brake pads, it’s better to replace the front rotors before the back if you cannot afford to do both at once. However, before you make a decision, ask the mechanic which axle is in worse condition, and focus on that one first.

Brake Cleaning

If the problem is caused by debris between your brake pads and rotors, or debris between your rotors and calipers, you’ll need to have your brakes cleaned. Brake cleaning usually costs no more than $150, and clearing this debris when necessary will extend the lifespan of all your brake components.

Auto mechanic spraying the brake disc rotor of a car to lubricate from rust and corrosion

Brake Lubrication

If your caliper screws or brake pads need to be lubricated, you may have more trouble nailing down an exact estimate without calling a few repair shops. If your brakes were installed without proper lubrication, you may be able to return to the same place and have them lubricated for free. If not, a repair shop should charge no more than $50 to lubricate existing pads or caliper screws.

Brake lubrication is included in the price of new installations. If your pads, rotors, or caliper screws have already begun to degrade, it may be easier to replace them altogether.

Should I Be Concerned About Grinding Sounds While Braking?

Generally, a grinding sound while braking at low speeds means there’s some kind of contact occurring that should not be. It’s one of the most common braking system issues, and most people will hear this sound at some point in their lives. Still, whether this is due to metal-on-metal or metal-on-debris, it’s a good idea to get the problem checked out by a mechanic as soon as possible.

Your car’s braking system is incredibly important in ensuring safe operation. If you cannot stop your car when you need to, you’re risking both your safety as well as that of other people on the road. For this reason, you should never let a grinding sound go unchecked for too long. It’s okay to use your car for daily errands, such as going to work or grocery shopping, while you’re experiencing grinding sounds. However, avoid making any long trips until you can get the problem diagnosed and repaired.

Mechanic inspecting the disk brakes of the car

Conclusion

Hearing a grinding noise as you press your brake pedal is never fun. While the most common cause is worn-down brake pads, the true issue could lie within any part of your braking system. It’s important to get this problem checked and diagnosed by a professional as soon as possible, otherwise you risk further damage and safety issues on the road.

References:

Eddie Carrara

AutoVfix

Rx Mechanic

The Motor Guy

My Sweet Indulgence

Car Care Lab

Noise When Braking at Low Speed: 7 Reasons and Solution 2022

Brakes To-Go

BRAKE PAD REPLACEMENT COST GUIDE

Norm Reeves Toyota San Diego

Why Are My Brakes Grinding?

Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

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