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Why Does My Car Shake When I Brake? 6 Common Causes

Why Does My Car Shake When I Brake? 6 Common Causes

If you’ve ever noticed your car shaking, the steering wheel going a little haywire, or your seat vibrating when you hit the brakes, it’s a cause for concern. You may be wondering: why does my car shake when I brake? Is this normal? How do I fix this problem? All the answers you’re looking for are right here.

How Do Brakes Work?

How Do Brakes Work

If you’re here to investigate: “why does my car shake when I brake”, the first thing you need to know is how brakes work. Brakes utilize the force of friction to drastically reduce the momentum of your vehicle.

A car in motion possesses kinetic energy that you need to get rid of to stop the car. But according to the first law of thermodynamics, energy cannot be created nor destroyed, it can only be transformed. Therefore, in order to stop a car in motion, friction converts that kinetic energy into heat energy. But how?

When you press down, there’s a connected lever that presses a piston through the master cylinder that is full of hydraulic liquid. The force generated by pushing your foot on the brake is amplified by the hydraulic system. It squeezes the hydraulic fluid out the end and around the entire braking system via a network of brake lines.

All four wheels have wide cylinders situated next to the brake pads. The pressure from the hydraulic fluid is transmitted equally to all four brakes to generate friction between the brake pads and disc brake rotors, which stops your vehicle.

6 Possible Causes for Car Shaking When Brake

6 Possible Causes

There are a number of causes for this. But if this happens in direct response to hitting the brakes, the root is likely a dysfunctional braking system so you need to have it checked out as soon as you can.

Please note that all of the below stated reasons can apply to both cars at high speed and low speeds. The reasons have been divided that way because they’re more likely to be the case for the car shaking at certain speeds.

At High Speed

If your car shakes when you hit the brakes coming down at high speeds, you should pause to investigate immediately. Here are some of the possible causes.

#1. Unbalanced Tires

This tends to happen often when you’re driving at high speeds. You’re more likely to hit a bump or go over a pothole. When this happens, your car’s wheels can get out of alignment or become imbalanced due to a loose bolt for instance or perhaps the tire coming off the rim. Tires should be the first thing you investigate if you experience the car shaking.

#2. Low Tire Pressure or Flat Tire

If the air pressure in each tire is uneven, it can cause the car to shake while driving. If you’re driving at high speeds with a flat tire, your car might shake drastically and cause skidding when you apply brakes suddenly. You need to ensure your tire pressure is at the proper level before you set out on long journeys.

#3. Brake Stuck to Wheel

Another possible reason your car might be shaking at high speeds is that the brake caliper is stuck to the wheel. The brake caliper is the mechanism on your wheels that pushes the brake pads against the rotors to stop your wheel from spinning.

If any one of them gets stuck clamping the rotor, it produces shaking when you apply breaks because of the uneven pressure being applied to all the rotors.

At Low Speed

Say you hit the brakes at 20mph and still experience shaking. Why does my car shake when I brake at low speeds? It’s more likely there’s a problem with the braking mechanisms.

#4. Imbalanced/Damaged Rotors

If shaking occurs when you’re pushing the brakes at a low speed, there’s a greater likelihood that there’s a problem with your rotors, although all of the above reasons for high speed can apply.

Your car’s rotors are what connect the brake pads to the wheels when you hit the brakes, and you can find them coupled to each wheel. It’s possible that your rotors may have been deformed or warped because of rough usage or a minor accident.

#5. Worn Brake Pads

One way that rotors get warped is due to the wear caused by the friction from your brake pads. Brake pads are also subject to physical deterioration from prolonged use. They’re not made to last forever. The average brake pad lasts between 30,000 miles and 70,000 miles.

Other factors such as weather, the terrain you drive on, and the way you apply brakes may also affect the longevity of the brake pads. But in any case, it’s only a matter of time before they need replacing. The right time to replace them when there’s roughly 1/4th of them left.

#6. Out Of Round Drum Brakes

Cars with drum brakes work a little differently. Out of round drum brakes require a flat surface in order to apply even pressure. However, due to the effects of weather, corrosion, and normal wear, they can develop an uneven surface.

This can make the pedal start pulsating or the car starts vibrating when you hit the brakes. Sometimes, there’s also a squealing sound accompanying, letting you know your drums need fixing.

How To Fix It

The first thing you need to do is diagnose the problem, because if there’s a simple way to fix it, getting it diagnosed at a garage would only cost you unnecessarily. If the shaking occurs simply every time you drive, start with the tires.

If there’s simply a problem with the tires, there are a number of DIYs on YouTube you can follow on how to fix a flat, restore the tire’s balance, replace certain parts, or replace the entire tire itself.

However, if the vehicle only shakes when you apply the brakes, that’s when you need to diagnose the rotors and brake pads to check for wear or misalignment. In most cases, it will require professional technicians to fix it.

FAQs

What Do I Do If My Car Shakes When I Brake?

If the tremors are medium to violent, stop the car, it may be risky to drive. You may need to contact a towing service to help you take it home or to a garage. If the tremors are mild, you can drive it back home or to a garage if you have the time to get it fixed, while maintaining a conservative speed with readiness for the handbrake.

How Much Does Replacing a Rotor or Brake Pad Cost?

It depends on the brand or the make of your car. High-end cars would naturally cost more to fix. But for the average car, a complete brake repair job that includes pads, rotors, and caliper replacement typically costs between USD 300 and USD 800.

A Few Parting Words

Why does my car shake when I brake? To summarize, if it only shakes when you brake, the problem is probably in your braking system. If you’re on a motorway and experience problems with the brakes, you can use the hard shoulder to stop your car but remember to switch on your emergency lights so other drivers know you’re there and avoid crashing into you.

About Author

Priscilla Dreher

Known for her travel blogs, Priscilla Dreher started out as sociologist in her career only to combine her love for writing with her penchant for philanthropy in the later years. A widely traveled author, Dreher has championed many human rights causes and continues to advocate for socio-political inclusivity in all her writing.