There is rarely a car-related issue that is as annoying as squeaky brakes. That high-pitch, irritating sound that comes on every time you hit the brakes is enough to drive a person insane. That being said, squeaky brakes can be much more than just an annoyance. Depending on the cause, this condition could indicate that your brakes are in need of immediate service. Let’s find out what causes squeaking brakes, and what you can do to fix them.
What Causes Squeaky Brakes
When you put the concept behind brakes on paper, the entire thing looks fairly simple. You have a rotor that spins with the wheel, two brake pads that sandwich it from each side, and a caliper that applies pressure. When you push the brake pedal, hydraulic pressure forces the caliper to clamp down on the pads, they bite into the rotor, and the car slows down.
That’s the quick explanation. Once you scratch the surface, you’ll realize that brakes aren’t that simple. Several things are happening behind the curtains, which you don’t really notice unless something is wrong.
Squeaking brakes are a result of these background processes, or more specifically when there’s something wrong with them. With that said, what we’re about to discuss are benign sources of brake squeal. We’ll touch upon the more serious causes later on.
Common Reasons for Non-Hazardous Brake Squeak
Pushing the brake pedal results in friction between the brake pads and the rotor that is either progressive or immediate. A byproduct of this friction is vibrations. Each component in the chain will vibrate at its own frequency. That means that your calipers are vibrating at a certain frequency, as are your brake pads and rotors.
When car manufacturers design cars, they put in a lot of effort into tuning (quite literally) the braking system components, so they all work quietly together. You’ll rarely ever run into a persistent squeal issue with factory brakes. It’s when you delve into the aftermarket segment that things become interesting.
Speaking of persistent squealing, let’s quickly get one thing out of the way – there is a persistent brake squeal and intermittent brake squeal.
- Persistent squeaky noise manifests every time you press the brake pedal, regardless of the temperature of your brakes.
- Intermittent squeaky sound is present only for the first few brake pedal applications and is quite normal
Intermittent brake squeak usually happens early in the morning while your brakes are damp and cold. It takes only a red light or two to get them up to temperature, dry and noiseless. This type of brake squeak is nothing to worry about.
Persistent Squeaky Brakes and How to Fix Them
Going back to the topic of vibrations, we need to mention that not all brake components will work well together. Sometimes the vibration frequency of your caliper isn’t going to be compatible with the frequency at which your new aftermarket pads are vibrating at. This incompatibility of frequencies is enough to cause your brakes to produce a high-pitched noise.
Fixing this particular issue comes down to two solutions — you can either get a new set of pads, or you can have someone tune the brakes.
Most people aren’t keen on wasting money on a new set of pads, especially if you just got yourself a set of quality performance pads. Therefore, the latter solution is usually what most people go for.
There are two ways you can tune the brakes. You can either use shims or brake lube. Both of these methods have proven to be effective at solving noisy brakes.
Shims are pieces of metal that sit between the brake pad and the caliper. The idea behind shims is to add a piece of material between the two independently vibrating brake system components, that would serve as a buffer. Most new higher-end brake pads come with shims already installed, but you can also get them in the aftermarket.
The other option is to use brake lube. Lube is most commonly applied at the points where the caliper bracket and pads touch. Just like with shims, the idea here is to remove empty space between the two brake system components and have them vibrate at the same frequency. Generally speaking, it’s a good practice to apply some lube when installing new brake pads.
Dangerous Causes of Squeaking Brakes
All we’ve mentioned so far are issues that won’t compromise your car’s ability to brake safely. Unfortunately, persistent squeaking brakes can be caused by other, much more dangerous problems.
Brake Pad Wear Indicator
The first thing on this short but important list is the brake pad wear indicator. Many new brake pads feature a small metal tab that extends over the friction material on the pad. It’s set up in a way that makes it contact the rotor when you wear the pad to a certain point.
The noise this tab makes when it touches a spinning rotor can be described as squeaking. That being said, some pad wear indicators produce more of a growling sound. Either way, the moment you notice that your brakes are making persistent noise, check the pads for wear.
Worn Out Pads
When you wear out your brake pads all the way, you’ll reach a point where the backing plate of the pad makes contact with the rotor. We don’t need to tell you how dangerous this is and why you should either replace the brake pads with a new set immediately or tow the car to a shop to get it done. A car with worn-out pads is NOT safe to drive.
Damaged or Worn Out Rotor
Worn-out or damaged rotors are another known culprit behind squeaky brakes. Sometimes rotors deform due to excessive temperatures or simply because of lacking quality control.
When they deform, their surface is no longer uniform. This can cause squeaky noise as well. Just like worn pads, warped rotors are nothing to joke about and need to be replaced with new OEM or performance rotors.
Always Use Quality Brake Parts
One way to avoid many of the squeaky brake issues listed above is to use quality brake pads and rotors. In addition to that, make sure to swap worn-out parts before they become a hazard.
Your brakes are the most essential system on your car making it imperative that you stay on top of your maintenance schedule. If you’re looking for quality brake system parts for your car, check out our catalog. We carry a complete range of Brembo braking components as well as other tier-one brands.