Knocking Noise When Braking: Should I Be Worried?

Breaks are one of the essential things in your car. If it starts malfunctioning, it can put many lives at risk. Thus, it’s no wonder why even a slight noise due to brakes can feel worrisome. When brakes are the issue, it’s no wonder why even a tiny noise matters. So, you may ask:

If I hear a knocking noise when braking, should I be worried? If you have a knocking noise when you press on the brake pedal, it usually comes from the rattling of brake pads in the brackets. In general, it’s not something worrisome as the brakes will still work. However, it would be best if you still fixed it. Thus, you’ll want to buy a specific tool, for that matter.

Braking noise indicates a problem or issue with your car’s braking system. Although the issue might be minor, you’ll still want to have it fixed so you can always ensure safety by lessening the risks brought by a failing brake.

In this article, you’ll see an in-depth article that will explain the probable cause of the knocking noise when you’re braking. This way, you’ll have an idea of the part that you need to check if you ever hear a knocking sound when you step on the brake pedal.

Without further ado, let’s get into it!

Knocking Noise When Braking

Why Is My Car Making a Knocking Noise When Braking?

If you hear a knocking sound when you’re braking your car, it probably came from the brake pads that rattle in the brackets.

You can usually hear the knocking noise whenever you’re driving, and you step on the brake pedal. But, once you do, it will start generating the knocking noise that sounds worrisome.

A variety of reasons can cause brake pad noise or knocking brakes, and the first step you’ll want to do is to double-check that you have the right parts for your vehicle. Many brake pads have a similar appearance, and it’s simple to purchase the wrong components.

Using the undersized improper components may be harmful since excessive brake rattling can cause the pads to move in the caliper and become stuck, causing the brakes to stop working correctly.

A knocking sound from a rattling brake pad can also cause the pads to skew sideways and jam in the caliper, distorting the backing plates and shattering the friction material, creating significant problems.

Another thing you can do is check the braking system on the driver’s side wheel. You’ll also want to check whether the caliper or rotor is damaged. 

If the noise only happens while decelerating to a stop, the brakes may be malfunctioning. However, if the sound persists, there is either a loosened suspension component or a transmission issue.

Should I Be Worried When My Car Makes a Knocking Noise When Braking?

If it’s the first time you hear the knocking noise as you step on the brake pedal, it’s not something to worry about too much. 

As long as you can still feel the brakes kicking in and that you’re slowing down, it means it may be due to a slight issue that needs adjustment.

As mentioned earlier, the knocking noise likely came from the brake pads that rattle in the bracket. If it’s only a quick knock and you want to test it out to confirm, you can step on the brakes while driving on a potholed path. 

If the noise is gone, it means that the pads are back to normal and are moving again. However, if the noise persists, you’ll have to fix it soon, or it may cause more problems if you continue to ignore it.

In short, you’ll only have to worry about a knocking noise if you feel that the brakes aren’t kicking and that you’re not slowing whenever you step on the brakes.

Now, even if it’s only a slight issue, you’ll still want to fix it soon so you can prevent the issue from escalating.

brakes that make knocking noise

How to Fix This Issue?

If you want to fix the knocking sound whenever you press on the brake pedal, you’ll want to know why it happens first.

Always keep in mind that the knocking sound isn’t the problem. Instead, it’s a sign that means you’re having a problem with your brake system and that you need to solve it soon.

Here are some of the things you’ll have to do to fix this issue:

Make sure you have the correct pads for your car’s brake.

One thing to look at is your brake pads and other parts. If you use a brake caliper or any other element of your braking system that isn’t compatible with your vehicle, you could hear a knocking sound.

Many brake pads have a similar appearance, and it’s simple to purchase the wrong components. It’s risky to use the improper parts that are too little. 

It’s because severe braking can cause the brake pads to move in the caliper, causing them to become stuck and stop working correctly.

Brake pad rattling can also cause the pads to skew sideways and lock in the caliper, bending the backing plates and breaking the friction material, creating significant difficulties.

So make sure you have the proper brake pads in your automobile if you hear any banging noises or brake pad rattling.

Be mindful when replacing the original parts.

When replacing brake pads and other parts, make sure you reuse or replace the necessary hardware that came with the original ones. Also, you must ensure that the replacement parts are compatible with your car and its brake system.

For instance, the old pads’ equipment typically involves stainless steel silver clamps on the reverse of the pads, which You can utilize if your new set of pads has no clamps.

Instead of stainless components, some producers employ a black rubberized shim. Never utilize both shims since this will result in an over-thickness scenario, causing pad drag and overheating. On brake pads, you need one shim set.

Clean the old parts that you’ll retain.

If you have the old parts and you’ll want to retain them, at least clean them and remove any rust or dirt.

Anti-rattle springs are usually present on the left and right spots of brake pads. Thus, if your original pad set had such shims, you should remove and clean it before reusing it.

Don’t damage the new and replacement parts.

Another thing you don’t want to do is damage the new parts. For instance, you don’t want to bend the shims from the new parts. 

Further, ensure you remember which direction you put them for the new setup before replacing them. 

While these end clamps or anti-rattle bands are removed, make sure the caliper slides into which these parts will attach are thoroughly cleaned.

Clean the parts from dirt or rust.

If the sliding ways are clogged with dirt or corrosion, the shims will not seat properly, causing the pads to jam in the caliper. It will result in braking noise or a knocking sound and the pads overheating the brake disc.

Do not put on a lot of lubrication.

Working on a brake means you won’t want a lot of grease in it as it can affect the brake’s performance.

These bits of hardware must allow pads to glide freely without contacting. You’ll also want to put a tiny amount of high-temperature oil to the pad backing plate ears where the anti-rattle clips are located.

This way, you allow the part to assist the pads in moving quickly. As always, take it as a rule of thumb to never get lubrication on your brake pads’ contact surface and apply lubrication lightly.


In summary, a knocking noise when braking isn’t something you need to worry about too much, especially if it’s your first time hearing it. The rattling of brake pads in the brackets is typically the source of a knocking sound as you step on the brake pedal. 

Thus, you can say it is not a cause for concern because the brakes will continue to function. Still, you need to keep in mind that it’s still a problem that you need to solve soon. As a result, you’ll want to invest in a specific tool to fix it.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more