What’s that noise? You’re probably wondering why do my brakes squeak? Are they supposed to sound like that? The sound of your brakes squeaking and grinding can be unsettling. Don’t panic. The condition of your car’s brakes is crucial for road safety. Therefore, if you notice that your brakes are making a squeaking sound you don’t want to ignore it. If the noise is accompanied by decreased braking performance you should have your vehicle serviced immediately.
Understanding How The Braking System Works
The brakes are a complex system that often confuses drivers. You may have heard the terms “brake caliper” or “drum brakes” casually thrown around but know exactly how they work together. Understanding exactly how your braking system works can provide some insight into why they start making noises.
The entire braking system relies on hydraulic fluid which keeps parts lubricated and aids in the transfer of heat. It all starts when your foot pushes down onto the brake pedal. This force activates hydraulic pressure in the master cylinder. The master cylinder is connected to the front and rear brake lines and it also serves as a reservoir for brake fluid. The primary role of the master cylinder is to transfer pressure through the hydraulic lines and hoses all the way to the calipers and then to the individual wheel cylinders.
Also, there are two types of brakes; drum and disc. Most vehicles are equipped with disc brakes which are mounted on the front and rear axles. The disc brakes are made up of calipers, rotors, pads, and other small mechanical parts. The rotors are a circular discs connected to the wheel hub and spin as the wheel moves.
The brake pads push into the rotors producing enough friction to stop the vehicle. The calipers are protective like housing over the rotors. It also holds the brake pads and is designed with ducting for the brake fluid.
The drum brakes consist of brake shoes that are fitted against the inner surface of the drum. The brake shoes, sometimes referred to as the pads, presses outward against the brake drum, producing friction that helps stop the vehicle. Disc brakes provide much more powerful stopping power which is why they are used in the front of the vehicle and the drum brakes are placed on the rear.
Why Do Brakes Squeak?
The sound of your brakes squeaking or squealing is made of vibrating waves. Depending on specific speeds, when a certain measure of pressure has been applied the friction produced can cause the loud squeaking noise that drives you crazy. The brakes are a metal disc that’s located right between two brake pads. When the pressure has applied the materials all rub together creating noise.
What Can Cause The Brakes to Squeak
As one of the hardest working components on your vehicle, the brakes are often put under a lot of stress. It can be completely normal to hear some type of noise from them as you are driving. Whether you have disc brakes, drum brakes, or both of them there are several reasons why your brakes may be squeaking including:
- While you’re driving it’s easy for dust, small rocks, and sand to make their way into your vehicle’s brakes. This can cause a squeaking noise.
- Rain, snow, or condensation cause moisture to build up on the rotors and pad which causes that squeaking noise. Moisture also causes rusting and this can lead to the infamous squeaking noise.
- If you use your vehicle’s towing capabilities, you’ll find that excessive loads can cause your brakes to start overheating leading to loud squeaking noises.
- When the calipers need to be lubricated or when they become seized this can lead to a squeaking or whistle light noise even when the brakes haven’t been activated.
- Installing cheap brakes or a bad brake installation job can lead to squeaky brakes
Usually, the situations described above will only cause your brakes to squeak temporarily. If the squealing noise persists there could be a bigger issue.
Squeaking Brakes and Worn Brake Pads
One of the most common reasons why brakes start to squeak is worn brake pads. The brake pads are the component that applies pressure and friction on the rotors to stop the vehicle. When the brake pads become worn when the driver steps on the brake they’ll hear a loud squealing or whining noise. This typically occurs when the metal wear indicator, which is a small tab of metal that scrapes on the rotor when it's time to install new brake pads, becomes exposed.
The brake pads aren’t something you can visually check like the motor oil or windshield wiper fluid. The metal wear indicators are meant to be a warning signal. So you should listen to your car when it starts talking.
How Long Do Brake Pads Last?
On average, brake pads should last for about 40,000 miles. For most drivers, brake pads last between 20,000- 65,000 miles. However, the longevity of your vehicle’s brake pads depends on your driving habits and the quality of the brake pads that are installed on your car. If you are a slow driver the brake pads on your car may last longer fast and aggressive drivers.
Why Do Brake Pads Wear?
Just like a bar soap that becomes smaller and smaller as you continue to use it, the brake pads become thinner as they wear. When you press down on the brake pedal, the brake calipers clamp down on the brake pads. In turn, the brake pads squeeze the rotor creating thermal energy or friction which brings the car to a halt. The brake pads constantly rubbing against the rotors whenever the brakes are activated causes them to slowly wear down.
Inferior Brake Pads
A cheap brake job may sound enticing but it will come back to bite you where it hurts. Inferior brake pads are made from low-quality materials. These cheap brakes come with years of annoying squeakiness. Inferior brake pads are made with large metal flakes and when you press on the brakes, the metal flakes rub against the rotors causing the squeaking noise. Over time as the metal flakes wear the noise may go away. The best way to avoid this loud noise is to invest in higher-quality brake pads.
Squeaking Noises Coming From the Rotors
Yes, the rotors can be the culprit behind the squeaky noises coming from your brakes. When moisture starts to build upon the rotors, a thin layer of rust starts to form on the surface of the rotor. As the rotors rotate the brake pads scrape all the rust off the rotors.
Particles from the rust get embedded into the leading edges of the brake pads which causes the squeaking noise. The only way to prevent this from happening is to keep your vehicle stored in a garage if possible. Typically, the moisture and condensation are a result of snow and rain.
The rotors can also make squeaking noises when they have been glazed or there are grooves on the surface. When the brake pads are worn the rotors develop grooves, or glazing occurs due to uneven wear. When you have new brake pads installed, the rotors need to be taken off, measured, machined. In some places, if they have become damaged or worn you may have to install new rotors.
If the mechanic doesn’t sand or smoothen out the glazes and grooves in the rotors this will cause them to make a squeaking noise especially when it’s cold. Sometimes, after the brakes heat the noise may go away but typically it persists until the rotors have been sanded down or replaced.
Over time as they wear rotors can lose their smoothness. This can lead to them making unpleasant noises as you drive or when you push down on the brake pedal.
Brake Calipers and Squeaking Noises
The caliper houses the brake pads and the pistons. A sticking caliper can cause squealing noises. When the caliper is stuck, the brake pads have constant contact with the rotors. When you’re driving the brakes will be slightly engaged at all times and you’ll feel as if you’re braking even when your foot isn’t on the brake pedal.
Being that the pads are continuously forced against the rotor this is what causes the squealing or screeching noise. Driving with stuck calipers can be difficult and can cause further damage to your vehicle’s braking system. This can also put stress on your transmission and can even lead to it failing prematurely.
Just like a sticking caliper, a stuck wheel cylinder can cause unsettling brake noises. When the wheel cylinder is stuck the brake shoes are constantly being forced against the drums.
How To Fix Squeaky Brakes
Fortunately, there are some things you can do to stop and prevent your brakes from squeaking. Here are the options you have when it comes to fixing this issue:
Change Driving Habits
The way you drive can affect how fast your brakes wear and it can also stop your brakes from making weird noises especially if you only tend to hear the squeaking when you are driving. When you’re frequently working the brakes hard, regularly transporting heavy loads, or applying them or steep inclines the brakes will heat up which ultimately causes the squeaking. Consider:
- Downshift into a lower gear when driving down steep inclines rather than constantly applying the brakes.
- Increase your following distance in traffic so that you don’t have to slam on the brakes or overuse them to avoid hitting other cars
- Reduce the pressure on your brakes by limiting your loads and using the appropriate vehicle for hauling.
The brake assembly is made up of several moving parts. They all need to be well-lubricated for the smooth operation of your brakes. A brake lubricant can be especially helpful if you have squeaky brakes that are a result of sand, dust, or rust. A light layer of lubrication should be applied to the sides of the caliper, pins, bushings, parking brake cables, and the linkages.
When you are lubricating these components you should exercise caution because you don’t want to get any of the lubrication onto the actual brake pads or rotors. After all, this can affect their stopping power.
Anti Squeal adhesive can be applied to your brakes to stop and prevent them from squealing. This adhesive is high temperature resistant and it is made from synthetic materials that are resistant to road salt and water. This product is different from a lubricant. It consists of a sticky film or fluid that’s applied to the area where the brake pad attaches. It absorbs the vibrations that cause the squealing noise. You can apply this product yourself or have your mechanic do it if you are unsure how to.
Use Quieter Brake Pads
Time for new brake pads? You’ll definitely want to make sure you install the right type of brake pads so they don't make a lot of noise. Semi-metallic brake pads are a popular choice because they are affordable. They do a great job at transferring heat away from the rotors but they are known for wearing rapidly and making a lot of noise. They also rust fast and produce dust which contributes to that squeaking noise.
When it comes to noise reduction, non-asbestos brake pads are a great option. They are made with organic fillers that reduce vibrations so they will be much quicker than semi-metallic brakes. However, non-asbestos brakes wear fast.
Ceramic brakes are expensive but they have great stopping power. These brakes also aren't really quiet. They also are rust-resistant and they don’t produce dust so you don’t have to worry about them squeaking. Ceramic brake pads are ideal if you haul heavy loads or if you regularly drive in stop and go traffic.
Get Your Brakes Inspected
Squeaking or squealing noises doesn’t always indicate a problem with your brakes. Since they are the most important safety feature on your vehicle you should have them inspected at least once a year.