Why Your Car Shakes When Braking

Most car owners who drive on a daily basis are able to tell when something goes wrong with their vehicles, with any sound, feeling, or smell that is out of the ordinary helping to point out that something is awry. When it's something jarring, such as when your car shakes when braking force is applied, we generally tend to assume to worst. Whether you're soaring down the highway in your BMW 3 Series or doing the school run in your Ford EcoSport, the feeling of a shudder through your steering wheel brake pedal vibrating is most disconcerting. There could be any number of reasons for a vehicle shaking when braking, so learning how to spot the symptoms and what they mean will be essential in keeping you and your passengers safe.

There are a variety of reasons for a car shaking when braking, and not all of them have to do with the actual braking system. There may be an underlying problem with the engine, or the tires might be improperly balanced. It helps to properly examine the symptoms of any vibration when braking, and exactly how and where the brake shudder can be felt. Sometimes, the fix is not the brakes, at all.

Shaking and shuddering can be felt at different points in your drive, and depending on when this symptom manifests, could be related to anything from worn tires to something more serious.

If you experience shaking from your car in the following scenarios, read on:

• The car shakes when braking and when accelerating
• The car shakes when stopped and idling
• The car shakes when turning or cornering

If your car is shaking constantly while driving or just idling, then the problem is probably not in the braking system. Some vehicles like pickup trucks have a natural level of vibration when running because of their body-on-frame construction. But for other cars, such as crossovers and sedans, there shouldn't be any noticeable shaking or shuddering as a matter of course. If you do experience this, here are some likely culprits:

• Wheel and tire problems: More often than not, the tires are to blame for a car trembling, whether braking or not. They may be unbalanced or the tire tread might have worn down unevenly. Incorrect wheel alignment can hasten this uneven wear, so make sure you've read up on wheel alignment issues here. Though less likely, it is also possible that the rims could be warped.
• Suspension or steering problems: If the suspension or steering system needs a little TLC with too much looseness, you may also feel the steering wheel of your car shake. If the shaking only occurs when you're turning, the likelihood of a worn or damaged wheel bearing is high.
• Axle: A bent axle, damaged driveshaft, or worn CV joints could also be responsible for dramatic shaking while you drive. Potholes, hitting curbs, or minor accidents are leading causes of damage to the axle.
• Engine and transmission problems: Lastly, the issue may lie with your engine or transmission. A broken or loose mount, or even a broken fan, will cause components to rumble about and vibrate the vehicle. Additionally, dirty spark plugs, faulty timing belts, clogged filters, or loose hoses can also contribute to a shaking sensation, too.

On the other hand, shaking can occur during times of deceleration, such as:

• The whole car shakes when braking
• The car shakes when braking at high speeds and low speeds

If your car shakes when pressing the brakes, then you can almost be certain the problem lies in the braking system. However, the exact cause may still be uncertain, and a closer examination will be needed. It is worth remembering that, under extremely heavy braking, modern ABS brakes rapidly pulse to prevent the system from locking up, and that is how they are supposed to work. We cover ABS braking extensively here. In most other situations, the likely culprits are:

• Uneven or worn brake rotors: Whenever the brakes are applied, the calipers apply pressure to the brake pads to clamp down onto the brake rotor to create friction and slow the wheels. This naturally causes wear on both the rotors and the pads. This is especially true when the brakes are applied heavily and frequently, as this causes overheating on the brakes. The high temperature increases the chances of warping and may even create a noticeable smell. If the surface of the rotors becomes too uneven, it can create brake shudder, which is when the brake pedal vibrates as you press on it.
• Worn brake pads: Most brake pads should last up to 50,000 depending on how you drive and use your brakes. If the brake pads wear unevenly it could produce a pulsing or shuddering feel that may cause the front end of the car to shake under heavy braking. This may even be accompanied by the sound of metallic scraping or grating.
• Calipers sticking: If one or more of the calipers get stuck, they won't apply even pressure to the rotors and this will create a shuddering sensation. This could continue after the brake pedal is released if the caliper gets stuck in the engaged position. Though not a caliper issue, electric cars may experience a similar problem to this if there is a problem in the programming of their regenerative brakes.

When you suspect that there is something wrong with your car, you should always get it checked by a professional mechanic. They may simply recommend that you replace your brake pads, but if the problem runs deeper, the rotors may need replacing, too. Of course, it may be as simple as realigning the wheels, if that is the cause of the problem.

As the old adage goes, prevention is better than cure, so ensuring your car is well maintained and driven with care will go a long way to preventing issues such as these. Tips for increasing the longevity of your brakes include driving cautiously with less intense braking, slowing down way in advance, and increasing following distance between you and cars ahead of you.