Why Do My Brakes Squeal?

Squealing brakes are a common automotive issue, and it can be more than just annoying. Brakes that squeal may be a sign of serious problems. Let’s take a look at some of the potential causes for that irritating noise.

The Squeal That Isn’t a Big Deal

First, let’s talk about the kind of squealing that you really don’t need to worry about. If your brakes squeal first thing in the morning but quiet down after the first couple of times you use them, the cause is probably just moisture.

Rain, snow, humidity, and condensation can lead to moisture and even a light coating of rust on the metal rotors. When the brakes are first applied under these conditions, it can cause a squealing noise as the brake pads scrape away the rust.

If dust and dirt has collected on the rotors, it can have the same effect. Either way, after a few applications of the brakes, the noise should go away. But if the noise persists, then you’ve got something more serious going on.

The Squeal You Shouldn’t Ignore

If your brakes squeal most of the time—or all of the time—don’t ignore it! This can be a sign of serious problems that could lead to expensive damage and even brake failure. And that can be seriously dangerous!

Some brake pads are actually designed to squeal when they’re almost worn out. These pads have a spring steel clip built into them. When the brake pad wears down to a certain point, the clip makes contact with the rotor, creating that squeaking or squealing noise.

These clips are known as “wear indicators” and that’s exactly their job—to let you know when your brake pads are worn down and need to be replaced, before any damage happens to the rotors.

If the brake pads aren’t replaced in time, then the brakes will begin to grind into the rotors. This can lead to damage that’s far more expensive to repair.

Another potential cause for squealing brakes is brake calipers that aren’t releasing properly. When the brake calipers stick, keeping the pads applied to the rotor, then the pads begin to overheat and eventually crystallize.

The crystallization affects the rotors too. Ultimately, this leads to squealing as well as decreased braking ability. And when your brakes don’t work the way you expect them to, that can lead to a serious accident.

Problems that cause looseness or vibration in the brakes can also lead to squealing. For instance, if the rotors are warped or are not properly resurfaced during a brake job, then the brake pad won’t be able to make consistent contact. Vibration results, which makes noise.

Likewise, if the brake pads don’t have insulation shims or insulation gel installed behind them, then they’ll vibrate and create noise. If your brakes start squealing right after the pads are replaced, this could be the cause.

Broken anti-rattle clips, unevenly worn brake pads, and brake pads with a high metal content are also potential causes of brake noise and squealing. If it’s your rear brakes that are squealing, it could be that you have drum brakes that need lubrication.

Ultimately, there are a lot of possible causes for squealing brakes, and some of them can be very serious and potentially dangerous problems. If your brakes squeal for more than a minute or two in the morning, don’t ignore it!

The fastest and safest way to deal with squealing brakes is to take your car in for service. Let your trusted mechanic diagnose and fix the problem before it becomes something much worse.