Following your regular brake maintenance schedule and replacing worn-out pads are excellent ways to keep your brakes in good working order. You wouldn’t expect to hear any worrying brake noises after replacing your pads. But what if you hear your new brakes squeak? This article will explain why this happens.
The short answer is no. If it was normal, new cars would have squeaky brakes right off the lot. Squeaking, when it does happen, is created by the resonant frequency of the squealing pad lining being amplified as it is carried into the caliper and caliper bracket. Since the resonant frequency may never be met on some vehicles the way it is on others, not all brakes squeal, even on identical vehicles.
Squeaking, when it does happen, is created by the resonant frequency of the squealing pad lining being amplified as it is carried into the caliper and caliper bracket.
– Richard McCuistian, ASE Certified Master Automobile Technician
Drum brakes don’t typically squeal as badly as disc brakes do, but they do make similar noises sometimes. Drum brakes tend to gather asbestos dust over time, which can cause drum brakes to squeak in a big way.
Whenever brake pads or shoes are replaced, the rotors or shoes are supposed to be either replaced or machined. Replacement rotors and drums have a braking surface that is especially prepared to be burnished after the brake pads are replaced. When rotors are machined, they should, while still spinning on the lathe, be lightly touched with a conditioning disk spinning on a drill to provide non-directional finish.
After the rotors/drums are machined, Bendix® recommends that rotors in particular be washed with soapy water after the machining process is done to remove the microscopic dust that remains after machining. Brake parts cleaner or other such solvents will not remove this dust as completely as soap and water. After washing with soap and water (hot soapy water is best), the braking surfaces should be dried with compressed air (wear gloves and safety goggles for this).
These microscopic iron particles from the machining process can be the source of squealing brakes and often is. But even if rotors or drums aren’t machined, squealing will be an issue due to improper seating of the friction material. Brake pad burnishing is almost never done in most shops or by most people who replace the brakes, but it’s an important step. On your first drive after brake pad replacement, perform 30 stops from 30 mph with a 30 second cooldown period (driving) after each stop. Do this in a non-traffic area so as not to cause issues for other drivers.
Brakes can also squeak because of underlying problems like low-quality brake pads, damage due to hard braking, poor lubrication, and stuck calipers.
It’s crucial to watch the symptoms closely and take your ride to an auto repair shop to ensure that your brakes are in good condition.
Here are some of the reasons why your brakes might squeak even if they’re new:
If you own a high-performance vehicle with semi-metallic pads, it’s somewhat more common for your brakes to squeak after installing new pads, but following the rules outlined in the opening part of this article will make it a lot less likely. There are also anti-squeal compounds that can be applied to the metal backing of the brake pad to prevent the squealing from being amplified by the caliper and its bracket. Many good sets of pads will have insulated metal shims permanently attached to the pad backing for this reason. But again, semi-metallic pads have metal fibers in them that will almost always be noisy if you just replace the pads without replacing or properly machining and conditioning the rotors.
Low-quality brake pads are more prone to squeaking because they tend to produce more brake dust. Some lower or medium grade brake pads aren’t quite so prone to squeak but may smoke and stink for the first few stops as the lining “cooks” during initial use. Once the brake dust gets in between the caliper and the piston, it can produce various brake noises. Make sure to get your brake pads from legitimate sources to ensure their quality. Squeaky brakes aren’t dangerous but can be annoying. Grinding sounds indicate more serious problems though.
Rain or snow can create corrosion on the surface of your rotors if the vehicle is parked long enough (like at the airport), causing your brakes to make unfamiliar noises, but it won’t typically be a squeak. Usually, that noise will be a roaring or rasping noise that will go away as the rust wears off. However, flakes of rust can become embedded in the pad material and create squeaking noises that weren’t there before.
During the break-in period, an even layer of brake pad material shifts to the brake rotors. Also called bedding, this process ensures that your pads are in sync with your rotors, reducing brake noise. Note the burnishing process described in the opening segment of this article.
Your driving style can affect your brakes. Frequent hard braking can produce too much heat and cause glazing on your pads. The glaze or glossy surface on the pads can cause a squeaking noise. Although mechanics can usually fix the problem by smoothing your pads’ surface, you wouldn’t want to risk your brake’s efficiency all because of your driving habits.
Poor backing plate lubrication might be an issue if your vehicle is equipped with drum brakes. Brake drums have tabs that ride against the backing plate and if these spots aren’t lubricated (do this lightly to keep it off the lining), you might hear a squeak as the shoes move outward. This is pretty rare, even if lubrication isn’t used there, but it can be an issue. In other words, your ride’s brake shoes should be properly lubricated so that they won’t scrape against the backing plate. This issue can easily be fixed by applying brake grease to the backing plate or the connecting areas of the shoes and the drum.
A more serious issue like a stuck caliper can cause squeaking. Even if you’ve recently had worn pads replaced, it’s still possible for your brakes to squeak. Calipers are supposed to push the pads against the rotors when you press down the brake pedal. Once these calipers get stuck, the pads can forcibly be squeezed against the rotors. This can produce noticeable brake noise. Note, however, that sticking calipers will cause other symptoms as well.
You should take your vehicle to an auto repair shop right away if your brakes start to squeak and the squeaking doesn’t stop. If you notice reduced braking efficiency along with the noise, there might be problems.
When you buy a vehicle, you are responsible for keeping your brakes in good condition. Many states have rules in place to monitor and regulate brake repair to ensure that all work is done safely. Although the laws vary from state to state, all states require a particular license for brake technicians.
Here are some tips for taking care of your car’s brakes:
The heavier your vehicle is, the more difficult it is for the brakes to bring it to a halt. Although it is sometimes unavoidable, removing unnecessary things from your vehicle will greatly benefit your brakes. Similarly, driving through mountains, steep hills, and rugged terrains regularly might place too much strain on your brakes. If you’re an off-roader, make sure to have your brakes checked regularly to make sure all your trips are safe.
Also, choose the brake pads that most closely match the way you drive. If you do a lot of hard stops or haul heavy loads, you’ll need different pads than if you just take your kids to the soccer match and drive to the grocery store. Typically, it’s best to use the highest quality pads you can afford, regardless, and replacing or machining the rotors when the pads are replaced is an excellent choice.
Lastly, you shouldn’t think twice about replacing faulty brake components. There are many top-notch brake pads, calipers, and rotors available on the market, so you’ll have no problem finding a replacement that’ll fit your ride. The best brake pads usually come with new anti-ratlle clips, and if your caliper won’t float (look this up), the pins or channels should be cleaned and lubricated.
If you’d like to know more about brake maintenance, check out our Ultimate Brake Maintenance Guide.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.