Why Does my Car Shake When I Brake?

By laura.cox

Posted in: 

September 28, 2022

Learn to diagnose shaking while braking in your car 

If your car shakes while braking, you have every right to be concerned. When your brakes struggle to slow your car, it means you need more space and time to stop, making brake shudder dangerous. Any problem with your car's braking system is serious and should be addressed immediately. If left unattended, the issue will only worsen, increasing the risk of brake failure and a possible accident. Most brake problems are less expensive to fix early before they can cause additional wear or even damage to other parts. 

Troubleshooting shaking while braking 

There can be many possible reasons why your car is shaking when braking. Paying attention to the kinds of vibration experienced while applying the brakes can tell you a lot about the type of problem your vehicle might be having. These can range from soft shudders in the brake pedal to the entire vehicle shaking and can indicate anything from misaligned tires to severe problems with the engine. 

When you experience: 

  • Brake pedal shaking: A vibrating brake pedal often results from rear rotor issues. 

  • Steering wheel shaking: This is usually a sign of front rotor problems. 

  • The whole car shakes when braking: This usually is a sign of brake system problems. 

You should also pay attention to additional shaking. If vibration is also experienced at other times during the drive, it can be a symptom of other automotive problems: 

  • Shaking when idling: If the vehicle vibrates while idling, it suggests an engine problem. 

  • Shaking during turns: If the car also shakes while turning, it can point to problems with the suspension, tires, wheel bearings, or more, and could be much more severe. 

  • Constant shaking: This is a symptom of many potential problems beyond just brakes and should get immediate attention. 

But if your car shakes when braking, the problem will likely be in the tires, brake system, or suspension. Here are some things you can check to identify the problem. 

Checking for tire problems 

The first thing to consider if your car is shaking while braking is whether your tires are the problem. Tires are the direct contact with the road, and any issues there will be felt during the drive. Some things to look for are: 

Worn tires 

As the tread on your tires wears down, your car will begin to lose its grip on the road. This increases your risk of accidents and can lead to tire failure. Other signs of tire wear will include: 

  • Loss of traction while turning  

  • Humming or thumping noises while driving 

  • Cracks, bulges, or blisters on the tire 

You can check your tread depth with a tread depth gauge, and you should inspect your tires for these signs as part of your regular maintenance routine. 

Wheel alignment issues 

If your wheels are improperly aligned, they will have several impacts on your drive, including vibration when braking. Other symptoms include: 

  • Vehicle pulling to one side 

  • Steering wheel settling off-center 

  • Noticeably uneven tire wear 

If your tires are in good working order, it is time to look for problems with the braking system itself. 

Brake problems 

Surprisingly, if your car shakes when braking, it can indicate problems with the braking system. Your vehicle will have one of two braking systems, and each can encounter different issues. 

  • Disc Brakes: These are the most common kinds of brakes, involving a disc that rotates with the wheel called the rotor. Finger-like calipers clamp a set of brake pads down around the edge of the rotor when the brake pedal is pressed, slowing the wheel with the rotor. 

  • Drum Brakes: Unlike disc brakes, these use brake shoes that are pressed outwards against a cylindrical drum inside the wheel itself. 

Some vehicles will have the same kind of brakes on all four wheels, but some cars will have disc brakes in the front of the car and drum brakes on the rear wheels. Regardless of the kind of brakes used in your vehicle, the brake master cylinder forces brake fluid through the braking system, translating the pressure on the brake pedal into the hydraulic power that stops the vehicle. 

disc-brakes

The things to look at on your brake system are: 

Rust or corrosion 

If the contact surface of the rotor or drum becomes corroded, it compromises the connection between them and the brake pads. You may feel the rough surface as vibration through the brake pedal. Other signs of brake corrosion will include: 

  • Sticking brakes 

  • Squealing noises during braking 

If your car shakes when braking, check your brake drums or rotors for dirt buildup, rust, or corrosion. 

Brake rotor warping 

In vehicles with disc brakes, the rotors may become warped through general wear combined with accumulated heat from the friction of braking. This compromises the connection between the brake pads and the rotors, resulting in problems such as: 

  • Vibrating brake pedal, sometimes only at low speeds 

  • Shaking felt through the steering column 

  • Squeaking or grinding noises when braking 

Rotors and brake pads are considered wear items on a car and should be checked regularly and replaced when they are worn or damaged. Careful driving that avoids excessive braking helps to prevent overheating and warping, allowing you to get the most extended life from your brakes. 

Brake drums out of round 

In vehicles with drum brakes, irregularities in the shape of the drum can cause a vibration when braking. As wear and tear affect the shape of the drum, the connection between the brake pads and the inner surface becomes rough. Some of the additional symptoms of out-of-round brake drums are: 

  • Brake pedal vibration 

  • Shaking during acceleration 

  • Scraping noises while braking 

  • Loose parking brake 

Like disc brakes, brake drums and pads wear down regularly and should be replaced when their effectiveness declines. This process can also be slowed by driving carefully and avoiding excessive braking. 

Brake pads worn 

In either disc or drum brakes, the brake pads make contact with the braking surface. As they are worn down by use, problems can develop, including shaking while braking as the brakes struggle to stop the vehicle. These problems include: 

  • Squealing noises as you brake 

  • Clicking as the pads shift in their brackets 

  • Longer braking times  

  • Nose drift when braking 

  • Grinding metal sounds when braking 

Brake pads are expected to last roughly 50,000 miles before needing to be replaced, though heavy use or irregular wear can reduce this lifespan. Check your brake pads for wear as part of your regular maintenance routine. 

Frozen brake caliper 

If one of the brake calipers in a disc brake is frozen, it will apply uneven pressure on the rotor and can cause shaking from the brake system. Because the car is fighting the constant resistance of the caliper, heat builds up quickly. This might result in rotor warping and subsequently cause further damage. Other symptoms of brake caliper problems include: 

  • Vehicle pulling to one side 

  • Grinding sound while driving 

  • Resistance while driving 

  • Fluid is leaking from the caliper 

  • Smoke or flames coming from the brakes 

A frozen brake caliper is rare but dangerous and should be dealt with before it can cause a severe problem. 

Air in the brake lines  

The brake lines that feed brake fluid into the brake system are meant to be airtight, and if air does manage to infiltrate, it will impact the performance of the brakes. If your vehicle shakes when breaking, it may be a sign that air has gotten into your brake lines. Other signs would include: 

  • Sponginess in the brakes 

  • Reduced brake effectiveness 

  • Brake pedal must be pressed farther before braking starts 

  • Low or leaking brake fluid 

If you have air in your brake lines, they need to be bled and refilled with new brake fluid. You should check the level of your brake fluid as part of the regular maintenance routine for your vehicle.  

Suspension problems 

Another source of vibration when braking is problems with the suspension. If the brake system stops an aligned wheel with decent tread, but the components holding that wheel to the car have issues, shaking can still be a problem. These are getting onto the more severe and expensive end of the scale. 

Worn shocks and struts 

Another probable reason your car shakes when braking is worn shocks and struts. Shocks absorb the vertical movement of the wheel from bumps and dips in the road, while the struts attach the wheel to the axle and the steering system. These also wear over time; as they do, they can be felt as vibrating brake pedals and steering wheel. Other signs of worn shocks or struts will include: 

  • Loose or drifting front end 

  • Bumpy and rough ride 

  • Vibration while driving 

  • Hydraulic fluid leaking 

  • Inconsistent tire wear 

  • Clunking when hitting bumps 

If you suspect you have worn shocks or struts, you should get your vehicle to a mechanic.  

Faulty wheel bearing 

The wheels on your car are each attached to a hub that contains wheel bearings. These lubricated bearings carry the vehicle’s weight and allow the wheel to turn on the axle with minimal friction. If a wheel bearing is worn or damaged, it can quickly become dangerous. In addition to a vibrating steering wheel, signs of a faulty wheel bearing will include: 

  • Squealing noises while driving 

  • Wobbling wheel 

  • Tires wearing unevenly 

  • Vehicle pulls to one side 

  • Humming sound from the wheel as it turns 

Faulty wheel bearings are dangerous, and the potential consequences include the risk of the wheel falling off the car while driving. A mechanic can replace the wheel bearing before it becomes a problem. 

CV axle problems 

Another potential cause of shaking while braking is a faulty constant velocity or CV axle. This turns the rotation from the transmission into the rotation of the tires and coordinates their movement to minimize friction. Other signs of a wearing CV Axle will include: 

  • Vibration while driving 

  • Clunking or knocking noises 

  • Clicking sound when the car turns 

  • Vehicle drifting to one side 

Like most suspension problems, a failing CV axle is dangerous if not addressed. If you suspect this is the source of your shaking vehicle, you will want to get it to a mechanic quickly. 

Resolving brake vibration or shaking 

In case you had not noticed, many of the symptoms of these problems are remarkably similar. Finding the specific cause of a vehicle shaking while braking is challenging, so you may need to take your vehicle to a mechanic to isolate the problem. Luckily, most of these issues are reasonably affordable to address. 

  • Lightly worn tires can be rotated and aligned affordably, but they should be replaced if the wear is too extreme. 

  • Problems with the braking system itself are more serious. If you are mechanically inclined, you could get a brake pad set and do a brake change yourself. Still, if you feel the least bit unsure, or if the repair is more involved, it is better to have a system as important as your brakes repaired by a professional. 

  • Suspension problems and engine issues will require a visit to the mechanic. 

Finally, the best time to solve a brake problem is before it happens. Driving carefully and checking your brake system as part of your basic car maintenance routine will help you catch these issues before they affect your vehicle's safety. 

Asking an online mechanic 

With so many potential causes for a car shaking while braking, it can be difficult and costly for a mechanic to find the exact problem. When this happens, it can be helpful to have a second opinion – particularly one that is not also charging you for the parts and labor. This is where the help of an online mechanic becomes invaluable. 

Talk to an independently verified online mechanic on JustAnswer and get an expert opinion you can trust so that you can make informed decisions. Explain the details of your problem, share photos of tires, brakes, rotors, etc., identify likely causes, and discuss your options. Why struggle to make an important automotive decision without that professional perspective?