A car shaking when braking from 60 to 80 mph can be caused by several issues, some more serious than others. Here are the most common culprits:
Warped brake rotors
This is the leading suspect. Rotors are the discs that spin with your wheels, and the brake pads clamp on them to slow the car down. If the rotors become uneven due to heat, wear, or other factors, they can vibrate when braking. This is often accompanied by a pulsating feeling in the brake pedal.
Imbalanced or worn tires
Unevenly worn or unbalanced tires can cause shaking at high speeds. So the steering wheel shakes even more when you brake. Look for uneven tread wear, bulges, or other damage on your tires.
Loose wheel bearings
These bearings allow your wheels to spin smoothly. If they become loose, they can cause wobbling and vibration on the wheel hub, which you'll feel through the car, especially during braking. You might also notice a shaking steering wheel.
Suspension problems
Worn-out shocks, struts, or other suspension components can allow the car to bounce excessively, which can lead to shaking during braking.
Sticking brake calipers
These are the components that squeeze the brake pad against the rotor. If a caliper gets stuck, it can cause uneven braking pressure, which can lead to shaking. Plus, it'll result in worn brake pads faster since the material is stressing progressively.
Intermittent ABS wheel speed sensor
This issue can develop due to faulty wiring, internal damage, or loose wheel bearings surrounding the ABS wheel speed sensor. The faulty sensor fails to measure the wheel speed correctly, making the ABS system react wrongly, possibly causing vibrations.
Worn brake pads
The brake pads alone can be responsible for the vibrations while braking. Similar to tires, uneven wear on brake pads can cause vibrations. Over time, the friction material on brake pads wears down and eventually loses its effectiveness. When this happens, the pads might not grip the rotor evenly, causing vibrations. Additionally, grease, oil, or other contaminants on the pads can reduce their grip and lead to uneven braking, resulting in shaking.
How do I know if my rotors are bad?
A bad rotor shows various types of symptoms, from noises to performance issues. You'll likely notice some more evident ones, but a few can go unnoticed for a while. So, try keeping these in mind if you suspect that your rotors are worn or too old.
Here are a few symptoms you might notice that indicate a worn or old rotor.
Vibration or pulsation
You might feel it in the steering wheel, brake pedal, or even the entire car when braking, especially at higher speeds like 60-80 mph.
Noises
Warped rotors can cause various noises like high-pitched squealing, scraping, or grinding when braking. These noises indicate uneven contact between the pads and the rotor surface.
Uneven wear on brake pads
If one pad seems significantly more worn than the other, the car shakes when braking. This could be due to a warped rotor causing uneven pressure.
Increased stopping distance
If your brakes feel less responsive and take longer to stop the car, warped rotors could be to blame.
Visual inspection
If you can safely remove a wheel and visually inspect the rotor, look for deep grooves, ridges, heat discoloration (blueish hues), cracks, or a significant lip on the outer edge. These are all signs of damage.
However, it's important to note that other factors can mimic these symptoms. Worn tires, imbalanced wheels, and suspension issues can also cause shaking and noise while braking.
Can low brake fluid cause the shaking?
No, low brake fluid doesn't result in vibrations when braking. Here's why:
How it works:
- Brake fluid transfers the force you apply to the brake pedal to the brake pads, ultimately slowing down the car.
- When the fluid level is low, there's not enough pressure in the system to ensure even and consistent braking force on all wheels.
The fluid itself won't cause shaking:
- This uneven pressure can lead to:
- Pulsating rotors: If one side of the rotor receives more pressure due to fluid imbalance, it can cause it to warp slightly, leading to vibration when braking.
- Sticking calipers: Low fluid can make it harder for the calipers to fully release, causing them to drag on the rotors even when you're not pressing the pedal. This causes vibrations.
Can I keep driving if my car constantly shakes at high speeds?
No, it's highly inadvisable to keep driving if your car shakes at high speeds. It's a significant safety hazard and could lead to an accident. Here's why:
Loss of control: The shaking can affect your ability to steer and control the vehicle, especially at high speeds, increasing the risk of an accident.
Worsening damage: Continuing to drive could worsen the underlying issue, leading to more expensive repairs later.
Potential for catastrophic failure: In some cases, the shaking could be a sign of a critical issue like a failing wheel bearing or axle, which could lead to catastrophic failure while driving.
Here's what you should do instead:
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Pull over to a safe location: Find a safe place off the road to stop your car, like a parking lot or roadside shoulder.
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Turn off the engine and engage the parking brake.
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Assess the situation: If you can visually identify the problem, like a flat tire or loose lug nut, you might be able to address it yourself safely (if you have the tools and expertise). Otherwise, call for help.
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Call for roadside assistance or a tow truck: This is the safest option if you're unsure of the problem or don't feel comfortable fixing it yourself.
Remember, your safety and the safety of others on the road are paramount. Don't risk driving a car that shakes at high speeds. Get it checked by a qualified mechanic as soon as possible.
Can a bad alignment cause shaking when braking at high speeds?
A bad alignment can contribute to shaking when braking at high speeds, but it's not the most likely culprit. Here's why:
The primary cause of shaking during braking
While misalignment can cause uneven tire wear, leading to some level of vibration, it usually doesn't directly affect braking. The more likely culprits for shaking during high-speed braking are:
Warped brake rotors: This is the most common cause, as heat generated during braking can warp the rotors, causing them to wobble and create a pulsating vibration felt through the steering wheel and car.
Imbalanced tires: Similar to alignment, an imbalance in tire weight can cause vibrations, but again, it's less likely to be the main factor when braking.
Loose or worn suspension components: These components play a crucial role in maintaining stability during braking. Worn or loose parts can lead to shaking.
Alignment's indirect contribution
However, a bad alignment can indirectly worsen shaking caused by other factors:
Uneven tire wear: As mentioned, misalignment can cause uneven tire wear, making the tire more susceptible to warping or imbalance, thereby amplifying the shaking during braking.
Increased stress on other components: Misalignment can put additional stress on suspension and other braking components, accelerating their wear and increasing the chances of shaking.
In short, can a bad alignment cause shaking when braking? Technically, yes, but indirectly. If misalignment leads to uneven tire wear, as mentioned earlier, it creates the perfect storm for warped rotors or imbalanced tires to wreak havoc during braking. However, it's rarely the primary culprit.
What to do
It's important to get your car checked by a qualified mechanic as soon as possible to diagnose the cause of the shaking. Driving with a shaking car can be dangerous, as it can reduce your braking performance and control of the vehicle.
Here are some additional tips:
- Avoid hard braking: This can put extra stress on your brakes and rotors, making the problem worse.
- Call a Shop nearby (you can find one here): Don't let any brake-related issues build up without a professional inspection; it's always best to be safer and rely on experienced auto shops.
- Don't ignore the problem: The longer you wait to get it fixed, the more likely it is that the problem will worsen and become more expensive to repair.
- Be aware of other symptoms: Pay attention to any other symptoms you experience, such as grinding noises, pulling to one side, or a soft brake pedal. These can provide clues to the cause of the problem.
Conclusion
Shaking when braking is a common issue that can be attributed primarily to problems with brake components rather than other causes, despite popular misconceptions.
While misalignment or other issues can contribute to vibrations, the root cause is often related to the braking system itself. One of the most common reasons for this shaking sensation is warped brake rotors.
Rotors can warp due to excessive heat buildup, often caused by prolonged or aggressive braking, which leads to uneven surfaces that cause the brake pads to pulsate against them, resulting in the sensation of shaking.
Another common culprit is uneven wear of the brake pads, which can cause them to grip the rotor unevenly, leading to vibrations. Additionally, worn or damaged brake calipers can cause uneven pressure to be applied to the brake pads, exacerbating the shaking sensation.
Other potential causes, such as suspension issues or tire problems, can certainly contribute to vibrations felt while braking, but they are typically not the primary cause. Proper maintenance and inspection of the braking system, including regular checks of the rotors, pads, and calipers, can help prevent these issues and ensure a smooth driving experience.
Addressing these brake component issues promptly can not only improve the driving experience but also ensure the safety of the vehicle and its occupants.
