The main reasons behind hearing a single clunk when braking are loose bolts, loose brake calipers, worn-out brake pads, contaminated brake fluid, cracked tires, dirt in the brake system, and worn-out rotors.
Keep reading this article to find out more about the issues that make the clunking noise when you brake your car and learn how you can fix them. We’ll also discuss the suspension system issues that can cause this problem as well. Let’s dive in!
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Single Clunk When Braking [7 Easy Fixes]
Hearing a clunk noise when coming to a stop indicates an issue with your braking system. Here’s a list of the most common reasons that cause your vehicle to make a clunking noise when you hit the brakes:
Note: You can also read how to fix a car making creaking noise when driving slow.
1. Loose Bolts
If there are loose bolts in the braking mechanism in your car, it can cause a single clunk noise when braking your car. You need to inspect the bolts thoroughly and see if any of them are loose.
The most common clunking parts in a car include the steering racks, struts, anti-roll bars, drive shaft, control arm, springs, tires, and wheels.
Check the bolts for all these parts and if you find a loose bolt upon your inspection, you’ve possibly found the culprit causing the problem.
Solution:
If you’ve successfully identified the loose bolt, the solution is simple. You need to tighten it to get rid of the clunking noise. Use a good-quality wrench and socket to tighten the bolt.
If the bolt in question is hard to reach, there are extension bars that you can use to tighten such a bolt.
2. Loose Brake Calipers
Brake calipers are an essential part of your braking system as they squeeze the brake pads against the rotors to make sure that the speed of the spinning wheel is slowed down and you come to a stop gradually. They’re attached to each of the wheels in your vehicle.
If you’re wondering what causes clunking noise when braking, loose brake pads could be the reason behind it. When they get loose, they don’t do an effective job of squeezing the brake pads and that’s what makes this noise.
There are other symptoms that you can be on the lookout for to make sure that your brake pads are truly causing the issue.
When there are issues with the brake pads, the brake light can come on, the car would vibrate during braking, and pull on one side. If you see all these signs, you have loose brake calipers.
Solution:
You can start by readjusting the brake calipers and see if that solves the problem. If the brake calipers are not just loose but also worn out, you need to replace them.
Good brake pads can easily last over 10,000 miles. So, you won’t need to change it again anytime soon if you replace it.
3. Worn-Out Brake Pads
If there were no brake pads, nothing would prevent the rotors in your car from getting damaged when you hit the brakes.
When you step on the brakes, the brake calipers engage the brake pads and the brake pads apply pressure on the rotors which are connected to the wheels.
This applied pressure creates friction and stops your vehicle from moving forward. If you hear a front-end clunk when braking, there may be an issue with the brake pads in the front of your car.
If you hear a single clunk from the rear when braking, the issue is with the rear brake pads.
Identify where you’re hearing the clunking noise from and inspect the brake pads in question. As mentioned, the issue can also be with your brake calipers. Check both components thoroughly for signs of wear and tear.
Solution:
If the brake pads are worn-out, you need to replace them. Unfortunately, brake pads are designed to wear out with time as their main job is to create friction with the rotors. Once you replace them with good brake pads, they should last 50,000 – 80,000 miles.
As a general rule to prevent this problem from happening, it’s a good idea to inspect the brake pads for wear and tear after every 5 months or 5000 miles of driving. That’ll keep you ahead of the problem and you can replace the brake pads before anything goes wrong.
4. Contaminated Brake Fluid
If you don’t have sufficient brake fluid or contaminated brake fluid in your car, it will cause issues with the brake system in your car. The brake fluid enhances the force you create with your foot when you apply the brakes and turns it into pressure.
With time, there could be several issues with your brake fluid. Though brake fluid is supposed to be part of a closed system, it’s common for brake fluids to have moisture in them and have an air leak into them. That makes the quality of the brake fluid deteriorate.
When there’s too much air or moisture going into the brake fluid, it can cause a clunking noise when braking slowly as it will have difficulty doing its job. Corrosion in the brake lines can also cause the brake fluid to go bad.
There are usually inhibitors and antioxidants in the brake fluid that prevent corrosion. But with time, they lose their effectiveness and the build-up of contaminants ruins the brake fluid.
How do you know if you have bad brake fluid? If the pedal in your car becomes too soft and goes down without much resistance, it’s a good indicator that you are running low on brake fluid. The ABS light can also be turned on when you don’t have enough brake fluid.
Solution:
When there’s too much air in the brake fluid, there could be a huge leak that causes the air to go inside. The brake fluid can leak from a number of places such as the rubber hoses, brake calipers, and master cylinder.
You have to identify and stop the leak to prevent it from making a clunking sound. The next thing you need to do is to drain the old brake fluid and replace it with fresh brake fluid. Make sure you get the brake fluid of the right viscosity for your car.
Check your owner’s manual to confirm what’s the right brake fluid viscosity for your car if you’re not sure about it. Drain the old fluid by taking off the cap from the master cylinder and removing it as much as you can. Then, fill it back in with the fresh fluid until you reach the max line.
You’ll need to top off the brake fluid multiple times to get there as you’d need to bleed the fluid from the components like brake calipers one by one. The fluid in the master reservoir will keep coming down. So, refill it when necessary and seal the cap when you’re done.
5. Cracked Tires
An issue as simple as a cracked tire can also cause a clunking noise in your vehicle. If there are large cracks or significant wear on any of the four tires, they could be catching the brake pad and causing the noise.
Solution:
Do a thorough inspection of all four tires in your vehicle and check them for cracks. If they are worn out, you need to replace them. Make sure that all the tires are inflated equally and to the correct level because uneven tire pressure can also cause this problem.
6. Dirt In The Brake System
If you’re still wondering why does my car clunk when you brake, the buildup of dirt or mud between the rotors and brake pads in your car could be a potential reason behind it.
If you drive through a muddy road, dirt and debris can get into your wheel and get caught up between some vital components in your braking system. As the residue remains between the rotors and brake pads, they make a noise when you step on the brakes.
Solution:
The brake pads and rotors need to be cleaned. It’s easy to take off the brake pads but it does take some time as you have to disassemble the tire, and get past the brake calipers to access the brake pads. But once you get your hands on the brake pads, you can clean them with a soft towel and solve the problem.
7. Worn-Out Rotors
The worst thing that can cause a single clunk sound when braking in your car is damaged or warped rotors.
If your brake pads get damaged and you don’t replace them in due time, the next thing that is prone to be broken is the adjacent rotor.
Solution:
You’d have to replace the rotors to get rid of the single clunk noise when braking in your car if they’re worn out. It costs around $40 -$70 for a rotor and you’d also most likely have to replace the brake pads with them.
Can Suspension System Issues Cause Clunking Noise When Braking
The suspension system and brake system in your car are closely connected to each other. Issues with the brake system can be a result of problems within the suspension system. Unfortunately, the list of things that can go wrong with the suspension system is also long.
Here are the most common issues that can cause problems with your suspension system and cause the clunking noise when you brake your car:
i). Worn-Out Struts
Struts help keep the car stable and ensure that you have a smooth ride. But when they go bad, they can cause the dreaded clunking noise. There will be more movement from your vehicle if you have bad struts.
Lift the vehicle up using a jack stand to confirm if you have bad struts. Check if they’re leaking oil, have dents, or are completely worn out. If they are damaged, you need to replace them.
ii). Damaged Control Arms
Control arms keep the different components of the suspension system connected to each other. Besides braking, if you hear the clunking noise while making horizontal movements as well, you most likely have damaged or loose control arms.
Tightening the bolts will solve the issue if the control arm is loose. But you’ll need to replace the control arm if it has gone bad.
iii). Malfunctioning Ball Joints
The ball joints in your car enable a pivoting motion between the steering system and the control arm in your car. The motion of the ball stud can make it come loose and move around in the socket.
One of the early signs of ball joints going bad is hearing a clunking noise. Apart from the noise, some other warning signs of bad ball joints are excessive vibration of the car, uneven tire wear, and the car pulling on one side.
If you don’t replace worn-out ball joints in time, it can create too much space between the stud and socket. The ball stud can pull out from the socket and cause a wheel to become partially disconnected. So, replace faulty ball joints in due time to prevent these issues from happening.
iv). Damaged Shock Absorbers
One of the most important components of the suspension system is the shock absorber. They make sure that you have a smooth ride on bumpy roads by controlling the movement and rebound of the springs and keeping the car close to the ground at all times.
When the shock absorbers in your car go bad, you’ll have difficulty in braking and controlling the vehicle. That’s what makes the clunking noise and you’re likely to see cupping on the treads of your tires if they’re damaged. Replace them and see if it gets rid of the annoying noise.
v). Faulty Sway Bar Links Or Bushings
The sway bar stabilizes the vehicle and prevents it from leaning too much when making turns. There are sway bar links and bushings that help the sway bar stabilize the car properly.
But if the links or bushings wear out, it causes issues with the braking system and creates a clunking noise. You need to replace the faulty sway bar link or bushing to solve your problem.
What Could Cause Clunking Noise If I Don’t Have Disc Brakes
A car that doesn’t have disc brakes usually has drum brakes. There are no rotors, brake pads, or brake calipers in such a brake system. So, what could be causing the clunking noise in this case?
These cars don’t have brake pads but they have brake shoes. These brake shoes are curved pieces of metal with fixed friction on one side. When you hit the brakes, the wheel cylinder uses pistons to push the brake shoes against the spinning drum and makes the car stop.
When the surface of the drum or the brake shoe isn’t smooth, it can bounce back and cause a clunking noise. Get both the drums and the brake shoes inspected and replace them if needed.
Just like the rotors in a disc brake system, the drums of a drum brake system need to be resurfaced every now and then. Take good care of the brake drums and brake shoes to prevent this issue from happening in the first place.
FAQs:
What is the clunking noise when braking?
The clunking noise you hear when braking the car indicates an issue with your braking system and it can be caused by a wide number of issues that have already been mentioned.
Should I hear a clunking noise if the brake system is fine?
You shouldn’t hear a clunking noise if you have a healthy brake system. If you hear such a noise, you should immediately get it fixed before the problem gets much worse.
Is it okay to drive with worn-out brake pads?
You shouldn’t drive with worn-out brake pads as such brake pads will cause damage to the rotors. It’ll cost more to replace the rotors and brake pads when they get damaged. So, you’re better off replacing the worn-out brake pads.
Can a parking brake cable cause clunking noise when braking?
When the parking brake cable gets loose, it moves within its bracket and creates a rattling noise as it’ll most likely bump against the suspension components next to it.
When should I change from brake fluid?
Most car manufacturers recommend that you change the brake fluid in your car after every three years. But if you drive more aggressively, it’s a good idea to change the brake fluid after every 3000 miles of driving.
Conclusion
There are many reasons why you might hear a single clunk when braking your car. Both issues with the brake system and suspension system can cause this problem. We’ve covered all the common reasons that are behind this issue.
We hope that you’ll find out the exact issue that’s causing the trouble in your case and be able to solve it after completing this article. Leave a comment below if you have any more questions about the brake or suspension system.
About John M
John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.