There are better ways to say “I’ve arrived” than emitting a cacophony of high-pitched brake squeals. These noises are annoying, and your car shouldn’t be making them, but they’re relatively easy to eliminate for DIYers. Here’s how.
Why the whine?
Before diving into some of the causes and solutions to your brake headache, it’s worth noting that brakes will sometimes make noise. Intermittent chirps are normal, especially if you live in harsher climates. If you still have brake pedal feel and can scrub off speed as normal, there’s nothing serious to worry about.
Put simply, brake squeal is generally vibration. Specifically, the noise comes from the interplay between a brake disc, a caliper, and a pad. Affected systems will emit a noise when pressure is applied from the caliper on the disc. You can slam on the brake pedal or carry more/less speed into each braking maneuver, but your brakes could still howl because of the contact between your pad and the disc.
If you notice your brakes only make noise sometimes, it might be due to moisture-turned-rust on the surface of a disc or pad. This can happen as quickly as overnight, and there may be some squeal until all of the rust has been scrubbed from the components. Here again, this is nothing to worry about.
Track day enthusiasts with racing pads need to acclimate to some squeal. The material used to make performance brake pads is more resistant to heat and creates greater friction, which boosts the resonant frequency into the audible range. For this reason, many weekend racers either choose a pad compound that isn’t aggressive enough to make noise or swap pads for weekday commuting.
In these two instances, there’s no cause for alarm, but if you start to hear a shrill metallic noise rather than a consistent, high-pitched squeal, you need to tend to your brakes immediately. In this case, you’ve likely worn your pads down to the metal and are slowing your vehicle without any compound buffer.
What tools and products you’ll need
Here are some of the most important tools and products you’ll need to hush your brakes:
- Some form of hand protection (we’d recommend a pair of mechanics gloves with some built-in grip)
- Jacks and jack stands (Harbor Freight has some stellar deals on these year-round)
- Lug wrench
- Socket wrench (with multiple socket sizes to fit your vehicle)
- Teflon shim
- Brake grease or anti-seize
- Anaerobic adhesive
How to silence that noise
First, you’ll need to decide whether you want to dampen the noise or change the components to stop the sound altogether.
The first and simplest solution is to change your pads. Depending on which compound you choose, new pads at all four corners can be a bit expensive ($100-$200), but it’s the best way to remove the conditions that lead to squealing. If you’re using a Kevlar pad, you may want to try a metallic or ceramic compound. There are a million aftermarket pad suppliers, all of which promise the best pad life, stopping power, and price, so you’ll have to do some research on the best for your particular make and model. We recommend buying original parts from your local dealer or a trusted supplier like Bosch.
If you don’t want to swap pads, another option is to insert a Teflon shim between the pad and caliper piston. This won’t work for every brake system — some are engineered without any margin of space for a shim to fit without making the pad drag on the disc. You could wear down your pad to a point where it no longer drags with the shim, but that would be a waste of money.
Another, more temporary, solution would be to coat the brake pad with brake grease or anti-seize to buffer the vibration frequency.
The final, and perhaps best modification (according to Popular Mechanics) is to move the pad backing plate to the caliper piston or housing. Doing so increases the piston’s mass and changes the vibration frequency to a point where it won’t squeal. To get the plate to stick for longer than a few days, weeks, or months, you’ll need the right adhesive. Popular Mechanics suggests an anaerobic adhesive that applies like a film or goo. When you press the plate firmly against the piston/housing, the adhesive will stick like a vice and resist corrosion from dirt and water.
If the noise won’t go away, check whether or not your car has an open recall pertaining to brake-related problems. You can find this information online, or by calling your nearest dealership.