Why Your Brakes Squeak When Backing Up: 7 Reasons
Squeaking brakes can drive anyone nuts. You’re reading this article because you know firsthand how annoying squeaking brakes can be. In this article, I will show you why your brakes squeak when backing up, plus I’ll show you how to get rid of the squeaking once and for all!
Don’t put up with the squeaking any longer! This article will show you the common causes of brake squeal and how to fix it!
What actually causes brakes to squeal?
Several causes contribute to brake noise, it’s important to understand that although there are different causes, what causes the squeaking is vibration.
Vibration is the reason for all brake noise in the final analysis. It doesn’t matter if it’s hard material within the brake pad face or poorly lubricated brake components, the result is the same. Vibration is what makes the squeal you are hearing.
Some of the links you’ll find on this site are Affiliate Links. That means if you click on one of these links and end up buying something I may earn a small commission. This has no effect on your purchase price what-so-ever! Thanks for supporting Scoots Garage.
Why do your brakes squeak when backing up?
1. Brake Pad Material:
Brake pads are made from various materials, such as organic, semi-metallic, metallic, or ceramic compounds. Each has its advantages and disadvantages.
“Lifetime” brake pads offered at big chain shops are often metallic and hard as steel. They last for an extremely long time, however, their performance is terrible, plus the super hard material creates the perfect place for vibration when they contact the steel brake rotor. Think of it as rubbing two solid blocks of steel together, kind of like an old train screeching down the tracks.
Poor material in cheap brake pads is what causes the majority of squeaking while backing up your car
In a nutshell, metallic and semi-metallic pads are more durable and offer better performance, but they can be noisier than ceramic or organic pads. The high metal content in these pads can lead to increased friction and, consequently, more noise, especially during low-speed maneuvers, like backing up.
How to fix it:
Insist on using either original brake parts from the dealer, or use only the highest quality aftermarket parts.
2. Moisture and Corrosion:
Where a car is parked for a while, especially in damp or humid environments, the brake rotors can develop a thin layer of rust.
It’s unavoidable.
This “flash” rusting is a regular occurrence, however, it can cause a temporary brake squeal that can drive you nuts!
If your car’s brakes squeal first thing in the morning, chances are moisture is the cause. After heavy rain and or an extended period of sitting the brake rotors on your car can develop surface rust. If you have a brake squeak when backing up first thing in the morning that goes away after a few stops, surface rust may be your only issue.
How to fix it:
Apply the brakes a few times to burn off the moisture and rust on the rotors. This noise typically diminishes as the pads wear off the thin layer of rust using friction.
3. Brake Pad Wear Indicator:
Many brake pads are equipped with wear indicators or sensors. Mechanical sensors that can squeak consist of small metal tabs that contact the brake rotor when the pad thickness reaches a specific limit.
Brake pads get thinner and thinner as time goes by, and eventually, these tiny metal fingers make contact with the rotor, producing a high-pitched squeal.
The sound is a warning… Your brakes are ready for a changeout.
These squealers work best when the car is backing up because driving in reverse forces the finger in the opposite direction, raising the pressure on the brake rotor and making the squeal much louder.
An indication of needing new brake pads is the brakes squeal loudly when backing up, plus they squeal consistently down the road moving forward when the brakes are not applied.
How to fix it:
Replace the worn brake pads and check for any issues with brake binding.
4. Brake Pad Glazing:
Brake pad glazing occurs when the brake pads experience excessive heat, causing the pad material to harden and become smooth and hard. This is yet another result of using cheap brake pads that are too hard, stop terribly, and are poorly made.
Heat causes glazing, and glazing reduces the pad’s ability to create sufficient friction with the rotor, resulting in a much higher likelihood of squeaking.
Using high-quality brake pads will help you avoid unnecessary glazing of the brake pads.
You get what you pay for when it comes to brake parts.
How to fix it:
If there is enough brake pad life left you can disassemble the brakes and sand the face of the brake pads with sandpaper. This will remove the glazing and allow the brake pads to “seat in” against the rotor again.
5. Lack of Lubrication:
The brake caliper and pads slide on pins, bushings, and caliper brackets.
The moving parts of your brakes need proper lubrication to function smoothly. If the lubrication dries up or becomes contaminated, the caliper may bind and cause the brake pads to stay applied even when your foot is off of the brake. This will cause very fast brake pad wear and many other braking issues.
The telltale sign of binding brakes due to lack of lubrication or a brake caliper issue is, one brake pad will wear much more than the rest. I’ve seen many cars that need brake pads replaced just because one pad is metal to metal, while the rest still have thousands of miles of life left.
How to fix it:
Be sure to lubricate all sliding surfaces and pins with high-quality brake grease. Always add a light coat on the backs of the brake pads as well.
6. Foreign Objects:
The road is a great place to pick up crap that can get stuck in your brakes. Small stones, debris, or road dust can get trapped between the brake pads and the rotor, which can cause squeaking when the brakes are applied.
Use a good light and take a look at each brake caliper through the wheel if possible, sometimes a brake squeak can come down to a simple little pebble stuck in the right spot.
How to fix it:
Inspect the brakes, or have a pro do it to ensure there are no sticks or anything else lodged in one or more of your wheels.
Worn Brake Hardware:
Brake hardware includes shims, clips, springs, and other components that help the brake pads stay in place and operate quietly. Over time, these parts can wear out or become damaged, leading to brake noise, including squeaking.
A common problem with worn brake hardware is the following.
The vehicle is backed up and the brakes are applied, you hear a squeak and a “click,” then when you drive forwards and hit the brakes you will hear a single distinct click, after that the noise will not happen again until you back up. This is the movement of the brake pads either from worn hardware or a worn caliper bracket.
How to fix it:
Spend a little more and make sure to get all-new hardware with your brake parts.
7. Low-Quality Brake Components:
Cheap, low-quality brake pads, rotors, or other brake system parts meet different manufacturing standards than what your car was built with. A stubborn brake squeal when backing up may be a result of crap parts.
You get what you pay for when it comes to parts, especially brake parts. I highly recommend using good-quality parts. This will make a huge difference, not only in eliminating brake noise but in stopping efficiency as well.
How to fix it:
Cheap is just that, cheap, buy quality at the start and avoid regretting saving $20 bucks on the parts.
Wrapping up
Here are some best practices to use when working on brakes to ensure there is no squeaking when you are done.
To resolve brake squeaking issues, inspect the entire braking system thoroughly or have a pro check it out. Identify the specific cause of the noise and take the appropriate course of action.
Use this list to help you decide what to do. Depending on your issue you might need to start cleaning and lubricating components, replacing worn parts, or upgrading to higher-quality brake components.
All in all proper repair and maintenance, efficient driving habits, and using the recommended brake parts can eliminate brake noise and ensure optimal braking performance.
