Why Do My Brakes Making Squeaking Or Squealing Noise

Normally your brakes are supposed to be a silent partner in the business of getting your car to stop safely. So when you step on the brakes, and they start to squeak, squeal, or make high-pitch grinding noises, you’re only right to worry.

There are a few different things that could be going on here. Worn brake pads, rusty brake pads, and moisture in the brake system all rise to the top of the list. Though warped rotors, brake dust, and brake quality issues are also in play.

To come to grips with whether or not this is a serious problem or something that might clear up on its own, we’re going to have to take a little bit of a deeper dive into your car’s brake system and what you might be able to do to solve it.

How a Car’s Brake System Works

How Does a Car’s Brake System Work
Animation on How Power Brakes Work

Most modern vehicles have disc brakes with a disc rotor made from heavy-duty iron, though there are some made from carbon fiber or ceramic material. The disc rotor is connected directly to the hub of each wheel.

When you step on your car’s brake pedal, a system of hydraulic components pushes pressurized brake fluid through lines to the brake caliper. This creates a direct relationship between the bottom of your foot and the piston inside each brake caliper. The harder and faster you press the brake pedal, the harder and faster the brake caliper is squeezed down.

The brake caliper has brake pads that might be made from an amalgam of materials, an alloy of metals, or ceramic with copper fibers. These materials are softer than the disc rotor and capable of producing friction without failing when they heat up.

When you step on the brake pedal, the calipers immediately respond by squeezing the brake pads down onto the brake rotor. The friction of the brake pads pressing onto the rotor helps slow the wheels down.

In a car with an automatic transmission, the hydraulic torque converter gradually disengages the gear of the transmission when you firmly apply the brakes. This reduces the power being sent to the drive tires. Not only does this reduce the force on the brake pad and rotor, but it also makes for a smoother braking experience in a shorter braking distance.

How Brake Pad Material Affects Brake Noise & Performance

The material your brake pads are made out of will factor heavily into the noises they make and the potential complications you might experience as they wear down. Modern brake pads are either organic, metallic, or ceramic. The composition of each can affect brake noise and pad life.  

1. Organic Brake Pads

Organic brake pads are one of the most popular and cheapest types of pads you see outfitted on commuter cars. Chances are good; this is what your current brake pads are made from.

Though you shouldn’t let the name lead you to believe they’re eco-friendly brake pads. They’re made up of an amalgam of materials such as rubber, special carbon compounds, glass or fiberglass, and sometimes Kevlar. All these fibers are bound together with resin.

Organic brake pads tend to make less noise and produce less brake dust over the life of the pads. They produce minimal heat from friction, reducing the wear and tear on the rotors and other brake system components.

Unfortunately, organic brake pads tend to wear out faster than metallic and ceramic pads. They also don’t handle extreme temperatures well.

The average lifespan of organic brake pads is between 30,000 to 50,000 miles. However, some high-end organic brake pads can last up to 70,000 miles before needing to be replaced.

There can also be modest quality differences between organic brake pad manufacturers. Many online reviewers found CarQuest to make some of the best organic brake pads.

2. Semi-Metallic Brake Pads

Semi-Metallic Brake Pads

Semi-Metallic brake pads are more durable than organic pads and are preferred for heavy-duty vehicles and cargo carriers.  They are often made from a composite copper, iron, and steel alloy, with a graphite lubricant and other fillers.

Though the percentage of metal and types of metal can vary from manufacturer to manufacturer, in some cases, this can increase the risk of rust, metallic debris, and brake dust in the braking system. Lower-quality semi-metallic brake pads are more prone to brake noise problems and rusting over time.

Semi-metallic brake pads have an average pad life of around 50,000 miles. However, rusting problems and poor brake care can shorten this number dramatically.

Most online reviewers found that Wagner and Bosch BP1108 semi-metallic brake pads were some of the top options for quiet braking performance.

3. Ceramic Brake Pads

Ceramic Brake Pads

Ceramic brake pads are becoming more common in modern-day cars. They’re made from a special, highly durable type of ceramic material and often have copper fibers embedded in them. They tend to be very quiet compared to organic and semi-metallic brake pads. Ceramic brake pads are also slow to break down and produce far less brake dust than other pad materials.

However, ceramic brake pads cost much more than the other two material options. Lower-quality ceramic brake pads can also be noisier than high-quality metallic brake pads.

Online reviewers found that Bosch and power stop ceramic brake pads were quiet and lasted longer than many of their competitors. All without sacrificing everyday braking performance.

9 Causes of Squeaky Brakes Noises

The most common reason for squeaky brakes is usually that the pads have worn down to the point that they need to be replaced soon. Though you shouldn’t just jump to this conclusion every time your brakes let out a mousey little squeaking noise. There are a lot of other things it could be. Some have quick fixes that you might be able to do on your own, and others might require a trip to the mechanic.

1. Worn Brake Pads

Worn Brake Pads

A lot of brake pads have a pad wear indicator built into them. They’re usually a little metal tab, sometimes referred to as a “Squealer,” that’s designed to make a high pitch squeaking noise when they make contact with the metal of the disc rotor.

When your brake pads are new, the pad material is thick enough to prevent the squealer tab from contacting the brake rotor. Eventually, it wears down, and the squealer tab starts making contact. This usually happens with the front brakes first, as they bear more weight from the engine and more braking force.

If you drive for too long with the squealers wearing, it can damage the brake pads. You also risk the pad wearing to the point that the caliper starts grinding on the rotor damaging both components.

The wise move is to call your mechanic and replace the worn brake pads. Though you probably do still have a week or two before you do any serious brake system damage.

2. Warped or Worn Rotors

Warped or Worn Rotors

Warped or overly worn rotors don’t have the smooth surface they need to smoothly meet the brake pads, which can manifest as squealing, squeaking or grinding noises. On the one hand, rotors have a natural lifespan of about 30,000 to 70,000 miles. However, every mile after 50,000 since your last major brake job should add a fraction of 1% or worry that your rotors are starting to wear out.

At the same time, excessive heat from friction and frequent hard braking can start to deform or warp the rotors. Heavy vehicles, like full-size pickup trucks that carry a heavy load, and cars in hilly or mountainous areas are more prone to warped rotors from frequent hard or prolonged braking.

A sensation of grinding or squealing noises when braking is just one indicator of warped or worn-out rotors. As the deformation in the metal surface worsens, you’ll start to notice vibrations and shuddering in the brake pedal and perhaps even the steering wheel. At this point, you’re definitely pushing the limits of whether or not the car is safe to drive.  

3. Low-Quality Brake Pads

Low-Quality Brake Pads

Cheap brake pads with low-quality filler materials, a low amount of graphite, or poor-quality metals in the amalgam of organic brake pads can create squealing or squeaking noises when they contact the rotors. This is more common with low-quality semi-metallic brake pads and some low-quality organic brake pads with an amalgam that’s high in metal but low in graphite.

If you recently purchased bargain basement brake pads, and they started squeaking after the brake-in period, then you should strongly suspect it’s the pads themselves. Lubricating the brakes might help, but you might not be completely satisfied until you replace them with higher-quality pads.

4. Damaged or Missing Brake Pad Clips

How to Install Brake Pad Retainer Clips

Brake pads typically come with pad clips that help secure the pads to the calipers while also helping to reduce vibration and noise. Sometimes a DIY mechanic will attempt to replace their brake pads at home and forget to install the clips. Once the new brake pads are broken in, you end up hearing squealing or squeaking noises as there are no clips to dampen the vibration.

If you recently changed your own brakes and you forgot to install the clips, you can place your palm to your head. Chances are good that you can still install the clips. However, finishing the job right the second time might take a couple of hours!

5. Loose Hardware & Uneven Pad Wear

Loose Hardware & Uneven Pad Wear

Loose hardware that causes uneven pad wear is another common cause of brake squealing after a DIY brake job. This is most often spring-loaded brake hardware that’s lost tension over time which can easily cause a squealing sound when you step on the brakes. However, many other lines, pins, and hardware components can come loose and/or vibrate to make a harmonic squeaking sound.

Loose or missing hardware can also cause the brake pads to slip slightly. The pad starts to wear unevenly with the rotor. This can cause vibration that manifests as squealing when you step on the brakes. Depending on how the brake pads settle into the caliper, you might even hear an uneven pad scraping or squealing for a few seconds after you set off again from a complete start.

6. Inadequate Brake Lubrication

Inadequate Brake Lubrication

Insufficient bake lubrication on the pins, calipers, and backing plates can cause a metallic squealing noise. While this can happen with disc brakes, it’s more likely to happen with rear drum brakes, where the shoes start to scrape against the backing plate, causing a squeal.

Inadequate brake lubrication is another common aftereffect of a hurried DIY brake job. If you’ve recently replaced your own pads, and they’re squealing like a wild pig caught in a trap, you’re going to have to go back in to apply some high-quality brake lube in all the right places.

7. Moisture on the Rotors

Moisture on the Rotors

Moisture condensation on brake rotors can mildly interfere with the friction relationship between brake pads and rotors, causing a sort of howling squeal when you step on the brakes. This is more likely to happen if your car has been sitting overnight during high, humid weather or you’ve been driving for a long time on a wet road without touching the brakes.

In most of these cases, the brakes make a sort of high-pitched howl when you first press the brake pedal that then vanishes as the calipers tighten the pads on the rotors. After a few stops, the heat and friction on the brake pads should evaporate the moisture.

8. Rusty Brake Pads

Rusty Brake Pads

If your car has been in storage for over a few weeks, a thin patina of rust on the disc rotors could cause the brakes to squeak or make a high-pitched grinding noise. This is even more likely to happen if the recent weather is wet or humid. It’s more likely to happen with semi-metallic brake pads, where rust also develops on the pads. You might even be able to see it on the rotors when you take a tire off.

The squeaking noise will usually transition into a light grinding noise and vanish within a few days. This is just the rust being ground off by the friction process. However, if you have semi-metallic brakes or organic brakes with a high metal content rusting like this can shorten the lifespan of the pads.

In a severe case of brake rust, the rust might take a week to grind off to the point that you get down to the squealers. Though with a keen ear, you’ll notice a difference in the squealing sound frequency.  

9. Brake Dust

Brake Dust

Brake dust can interfere with the friction relationship between the brake pads and rotors, making a squealing noise. This is even more likely to happen with low-quality brake pads and semi-metallic brake pads. If your car has rear drum brakes, the dust from the shoe grinding on the drum can make a lot of dust. Though you would only hear the squealing noise coming from the rear brakes.

As a brake dust problem persists, you’ll notice that one set of wheels looks cleaner than another. The dust can start to mar the cosmetic appearance of the once-shiny rims and hub caps. It’s usually associated with the brakes wearing down to the point where the pad squealers are making contact with the rotors.

How to Stop Your Brakes from Squeaking Or Squealing

Stopping brakes from Squeaking Or Squealing can be as simple as replacing the brake pads or updating whatever little thing you forgot to do during your DIY brake job. The underlying cause of the squeaking brakes will determine what, if anything, you need to do to make things quiet again when you step on the brake pedal.

1. Fixing Worn Brake Pads

How To Change Replace Brake Pads Easy Simple

If your brake pads are nearing 30,000 to 50,000 miles of life, then chances are good the squealer tabs rubbing on the rotors are telling you it’s time to replace them. If you’re a capable DIY mechanic replacing the brake pads won’t take you more than a few hours. Just be sure to properly install all the pad clips and hardware components as well as lubricate the caliper, the pins, and the brake pad backing.

The average cost for replacement pads and hardware typically runs between $35 to $125 per set of brake pads. Then you can expect it to take you about 45 minutes to an hour per wheel to get the brake pad replacement done right the first time.

The average cost of having a mechanic replace your brake pads is between $125 and $300 per axle for parts and labor.

2. Fixing Worn or Warped Rotors

How to Replace Brake Rotors on Your Car

If you catch the signs of a warped rotor early, you might be able to have a mechanic smooth it out by machining it on a lathe. This might only cost you $25 to $50 per rotor, which isn’t all that bad. Remember that this is still a heat-stressed metal that’s experienced some degree of metal fatigue.

Most machined rotors end up deforming again within a few months or within 10,000 miles. They’ll need to be replaced at that point, and the money you spend on machining the warped rotors will just be thrown out the window.

If the cause of your brake squealing is from badly warped or worn-down rotors, then you must have a mechanic replace them. This is usually right at the limits of what a capable DIYer can handle correctly on their own.

The cost to have a mechanic replace your rotors will run you around $175 to $250 per axle. Though you’ll also need to have the brake pads replaced simultaneously, or they’ll wear unevenly, shortening the lifespan of the new rotors.  

3. Dealing With Squealing From Low-Quality Brake Pads

How Do Brake Pad Shims Work?

If you tried to cut corners and went with the low-budget brake pads, you shouldn’t be too surprised if they start squealing even after being properly broken in. Sometimes you can get lucky. Lubricating the caliper and other moving components will diminish the squeal to a tolerable level.

Another thing to try is to install some shims to help eliminate vibrations in the relationship between the caliper and the brake pad. Some replacement brake pads come with shims, and some don’t. Most aftermarket brake shims are fastened firmly to the brake calipers and have a layer of rubber that buffers the vibration of squealing brakes.

If lubricating and installing shims don’t dampen the vibration and squealing, you might have to bite the bullet and invest in higher-quality replacement pads.

4. Fixing Hardware Problems After a DIY Brake Job

Fixing Hardware Problems After a DIY Brake Job

If you recently performed your own brake job, and the brakes are squealing like an animal caught in a trap, it’s a sure sign you forgot something or got something wrong on your first try. There’s no shame in that; everybody has a face-palm DIY repair from time to time.

Just remember that brake pads come with the replacement hardware they need to last just as long as the pads themselves. When the pads come to the end of their life, so do the pad clips and other hardware components. You can’t reuse the old pad clips from the last brake job on the next brake job.

Usually, fixing your DIY brake job is as simple as getting access to the caliper and making the updates. If you’re lucky, it’s as simple as installing the pad clips, making sure everything is lubricated, and possibly installing some shims.

5. How to Deal with Rusty Brakes & Brake Dust

Valvoline Brake Cleaner Instructional Video

Brake rust or brake dust on the pads and rotors that causes squeaking sounds can usually be cleaned away with brake cleaner spray and a meticulous wipe down. Ideally, you want a non-chlorinated brake cleaner that won’t affect the friction relationship between the brake pads and the rotors afterward. These multi-purpose brake cleaners can also be used to clean other dirty parts on things like your lawn mower or a string trimmer.

Our Product Choice (No – 1): Berryman 2420 Brake Parts Cleaner 14-Ounce

Our Product Choice (No – 2): CRC (05084-12PK) Non-Chlorinated Brake Cleaner

The process starts with loosening the lug nuts, then jacking the car up and blocking it off for safety. Most of the time, you can clean the rotor with the caliper and brake pads in place. If the rust or brake dust problem is severe, you might need to remove the caliper and pads. If so, be sure to take tons of pictures on your phone to make sure you reassemble everything correctly later!

Then you want to spray a heavy yet even layer of brake cleaner onto the brake disc rotor. Put a tray underneath it to catch any drips, and then give it 10 to 15 minutes to completely dry. Then wipe it off with a clean shop rag.

If there’s still some rust on the rotor, spray again and then lightly scrub it with some steel wool. Allow time to dry, and wipe it down again.

6. How to Lubricate Your Brakes

Doing This Will Make Your Brakes Work Better and Last Longer

If you performed your own DIY brake job, but you forgot to lubricate your brakes in the process, you should expect some uncomfortable squealing. Dealing with this usually calls for going back in and lubricating the caliper, the pins, and the brake pad backer.

Of course, you can’t use just any old lubricant. Oil and conventional lubes can interfere with the friction relationship between your brake pads and the rotors. You want to use a synthetic, non-petroleum, or silicone-based lubricant for any rubber or plastic components. For any metal-to-metal brake surfaces, you want to use a dry film lubricant that contains either graphite or molybdenum disulfide.

Our Product Choice (No. 1): CRC 3084 Dry Moly Lube

Our Product Choice (No. 2): Cerami-Glyde Tube Silicone Brake Lubricant

Brake Lubricating Tips

Wipe away any loose dust or dirt on the braking system using a soft cloth. Use a cotton swab to remove debris from any hard-to-reach places if necessary. This will ensure a proper relationship between the lubricant and the components.

Then spray the braking system with a high-quality non-chlorinated brake cleaner. Give it 10 minutes to dry, and wipe everything down with a fresh soft cloth.

After all the surfaces are clean, you can apply a small dab of lubricant on your finger or a cotton swab to carefully apply the correct brake lube for the component type. Do your absolute best not to get any lubricant on friction surfaces like the brake rotor or the face of a brake pad.  

When To Take Your Car Back to the Repair Shop

When To Take Your Car Back to the Repair Shop

If you’re within 30,000 to 50,000 miles since your last brake job, and your brakes are squealing, the smart thing to do is take your car in for a routine brake inspection. This usually costs under $50, and some oil change places will even offer it as part of a service package, including an oil change and tire rotation.

The brake inspection takes the guesswork out of the process, making it easy to figure out why your brakes are squealing. Once you know for sure what’s going on, you can decide if it’s within your depth to fix it or if it’s time to take it to a mechanic.

Frequently Asked Questions

Will the Squealing Brake Noise Go Away on Its Own?

If you only have a mild patina or rust on your brake rotors or the squealing is due to moisture on the brake pads, it should go away after a while. With all other causes of squealing brakes, the problem will most likely persist. However, you can accidentally drive on worn-out brake pads until the squealers are ground away to nothing. At this point, the squealing noise will go away on its own but be replaced by metallic grinding and rasping sounds right before imminent brake failure.

Is It Normal for New Brakes To Squeak?

New brakes can squeak for a few days or even a week or two after a major brake job. It just takes a little while for friction to even out the relationship between the surface of the new brake pads and the brake rotor.

You can also speed up this breaking-in process known as “Bedding.” This involves speeding up to 35 MPH and then lightly braking until you reach 5 MPH without stopping. Repeat three to five times. Then repeat this process at 55 MPH breaking hard down to 5 MPH. Then take the car for a light drive on the highway for 10 to 15 minutes before parking it to let the brakes cool all the way down for at least an hour.

Is It Possible for My Car’s Front Brakes to Wear Out but the Rear Brakes Are Fine?

Depending on your vehicle’s weight, size, and engine configuration, your front brakes can wear out much faster than your back brakes. The additional weight of the engine and the front stopping force the pads endure can accelerate pad wear by as much as 50%. In some older pickup trucks where the weight distribution is massively biased toward the front, the rear brake pads might last twice as long as the front.

Conclusion

If your brakes are squealing and it’s not due to moisture on the rotors or a little rust from sitting in storage, then you need to take the noise seriously. If you’re within 30,000 to 50,000 miles since your last brake job, the smart thing to do is take the car in for a brake inspection.

Chances are good; the noise you hear is the squealers on the edge of the brake pads telling you it’s time to change the pads. If so, make sure to choose mid to high-quality pads which have a longer lifespan. Ceramic brake pads might be more expensive than common organic brake pads, but they are worth it and less likely to have complications in the future.

If you’ve recently performed your own brake job, and you cut corners on the brake pad quality, or you tried to reuse hardware from the last brake job, you’re going to have to go back in to get the job right the second time. While you’re in there, make sure to use all the new connection hardware and lubricate all the non-friction moving parts. You might also want to install rubber shims on the calipers to dampen vibrations and reduce squeaking noises.

Jason Farrell

Written By

Jason Farrell

Jason Farrell is a certified master technician, the editor of Mechanic’s Diary in Pittsburgh, Pennsylvania. He is ASE (Automotive Service Excellence) certified and earned a Bachelor’s Degree in Automotive Technology from Pittsburg State University. With nearly 18 prior years of experience in the automotive field, he has extensive knowledge about Domestic, European, and other foreign makes and models of cars and light trucks. Jason’s experience working as a technician and service manager at dealerships, gave him the experience and know-how of most aspects of inspection, diagnosis, and repair from engine and drivability to electrical, HVAC, brakes, steering and suspension and everything in between.

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