Why Does My Car Jerk When I Brake? (14 Reasons Why)

The passengers of a vehicle always want to enjoy smooth driving. Sometimes, passengers may face different issues while traveling. The passengers always want smooth braking or acceleration. Nonetheless, if your car starts jerking when starting to accelerate or while braking, it could indicate an issue that needs attention. If you also face the same issue, you want to know why my car jerks when I brake. Don’t worry this article mainly explains the causes of the car jerk while braking.

Why Does My Car Jerk When I Brake?

The following are the major reasons of the car jerks when braking:

  • Manual Transmissions
  • Floor Mats
  • Worn Tires
  • Warped Rotors
  • Faulty Brake Power Assist
  • Hydraulics Issues
  • Worn Brake Pads
  • Bad Brake Calipers
  • Worn or Loose Brake Hose
  • ABS Issues
  • Faulty Fuel Pump
  • Faulty Fuel Injector
  • Low Brake Fluid
  • Air in the brake lines

1) Manual Transmissions

When driving a car with a manual transmission, inexperienced drivers may cause the vehicle to jerk while braking if they do not shift gears correctly during decelerating.

Manual Transmission, causes of car jerks while braking

For smooth downshifting, it is essential to coordinate the gear shifter, brake pedal, and clutch pedal. Inadequate coordination or inexperience in handling a manual transmission can lead to a jerky braking experience.

2) Floor Mats

Floor mats serve to maintain cleanliness and protect your car’s flooring. However, they can also contribute to a jerking sensation when braking.

car floor mats

If the floor mats of your vehicle become dislodged from their intended position, they may interfere with the operation of the brake pedal. This can cause the brake pedal to function unevenly when pressed, resulting in the car jerking.

In most cases, the solution is to reposition or replace the floor mats to eliminate the issue.

3) Worn Tires

Tires with insufficient tread or uneven wear may struggle to maintain a good hold on the road, particularly when driving on snowy, icy, or wet surfaces. This can cause the vehicle to jerk when you apply brakes.

Worn Tires

It is important to regularly check tire wear for safety reasons before assuming there is an issue with the brakes.

Read More: Worn Tire Symptoms and Causes

4) Warped Rotors

Warped Rotors

Over time, the brake rotor of your car can warp, particularly if it has been previously turned on a brake lathe.

Warped rotors can cause a car to shake when the brake pedal is pressed due to thermal shock from overheating or rapid cooling.

5) Faulty Brake Power Assist

The latest vehicle models typically employ a booster system to help the braking. Passenger vehicles usually contain a vacuum brake booster connected to the engine to amplify pressure, while heavier truck relies on the power steering system pressure.

Faulty Brake Power Assist

When functioning correctly, the power assist system eases braking for the driver by increasing the force applied to the brake pedals, enabling a smooth and safe stop.

However, if these components malfunction, the vehicle may jerk during braking. In such conditions, you need to repair or replace the brake power assist system.

6) Hydraulics Issues

In most vehicles, the braking systems depend on the closed hydraulic loop. This system has a master cylinder. This cylinder serves as the central component that responds to the driver’s use of the brake pedal.

Hydraulic fluid within the master cylinder is forced via the brake lines to each cylinder (drum brakes) or caliper (disc brakes)- similar to blood flowing through our blood vessels to our extremities.

Since this fluid does not compress under pressure, your brake activates as the pedal is pressed, forcing the fluid toward the mechanical braking parts. However, air can occasionally enter the hydraulic system, leading to a spongy brake pedal and potentially causing the car to jerk during braking.

Removing the air from the hydraulic system, or “bleeding” the system, typically requires two people, so it is not recommended to attempt this task alone unless you have prior experience and a helper available.

7) Worn Brake Pads

Worn-out brake pads can compromise the effectiveness of the braking system, potentially causing the car to jerk or shake while braking.

Worn Brake Pads

Furthermore, accumulated debris or dirt under the rotor due to worn pads can cause vibrations while driving, signaling the need for new brake pads.

If the brake pads of your vehicle are excessively worn and require replacement, the vehicle might shake violently with each press of the pedal. Such issues often stem from brakes jamming into their gear teeth, accompanied by grating or chattering noises.

8) Bad Brake Calipers

Brake Calipers, reasons of car jerks when applying brakes

A bad brake caliper is one of the major causes of jerks when you apply brakes. The bad brake caliper may result in insufficient pressure being applied to the brake pad, which may lead to the brake shake.

9) Worn or Loose Brake Hose

A faulty or detached hose in the brake system may also lead the jerky stops. In this case, hydraulic fluid may leak from the fluid reservoir, reducing the pressure transmitted through the brakes. This not only impairs your vehicle’s stopping ability but also creates a spongy sensation when pressing the brake pedal.

10) ABS Issues

The latest vehicle models are typically equipped with an Anti-Lock Braking System (ABS). This system is designed to prevent brake lock-up during a loss of traction.

ABS system

For example, when your car is sliding on the icy pavement while pressing the brake pedal, the ABS modulates hydraulic pressure to rapidly release and reapply the brakes. This maintains steering control while slowing down the car, eliminating the need to manually press the brake pedal.

During ABS activation, you may experience a jerk in your brake pedal. Without ABS, your brakes may lock up, causing the tires to stop rotating and resulting in a loss of steering control.

However, when you encounter jerking while braking and suspect ABS failure, you should immediately replace your ABS.

11) Faulty Fuel Pump

fuel pump

The faulty fuel filter or pump can also lead to car shaking, as the necessary fuel may not be adequately supplied. This issue may also lead to engine cranking without starting the vehicle. In such cases, it is best to consult a professional mechanic for diagnosis and repair.

12) Faulty Fuel Injector

Corroded or worn-out fuel injectors can prevent the correct amount of fuel from being sprayed into the combustion chamber, resulting in an improper air-fuel ratio. This can cause the vehicle to jerk when moving from a stop.

Fuel Injector

If the engine control module (ECM) monitors a rich or lean mixture, you can identify this issue using a diagnostic tool. When the fuel injector of your car goes bad, the ECM triggers the P0171 or P0174 code.

13) Low Brake Fluid

Brake fluid is crucial for maintaining your car’s optimal performance, as it is a hydraulic fluid that enables the smooth operation of pumps and pistons. Insufficient brake fluid levels may cause the car to jerk during braking due to compromised brake line mechanics.

Brake Fluid

Regularly inspecting your car’s brake fluid levels and checking for leaks can help prevent this issue. Additionally, the brake fluid reservoir or hose may be faulty, in which case repairing or replacing these components can resolve the issue.

14) Air in the Brake Lines

If air enters the hydraulic system, it may lead to a faulty brake pedal and jerking during braking. Bleeding the brakes can help remove the air and restore proper function.

How to fix a Jerking Car while Braking

To fix a jerking car, you need one or more following repairs:

  • Regular Maintenance: Ensure proper and regular maintenance of your vehicle and braking system.
  • Replace the worn brake pads: Regularly inspect the brake pads of your vehicle for damage according to the manufacturer’s recommendation and replace them if necessary.
  • Replace warped brake rotors: Inspect the brake rotors. If they are warped, replace them.
  • Replace bad brake calipers: If the brake calipers are not functioning properly, you need to repair or replace them.
  • Add brake fluid: Check the brake fluid in the fluid reservoir. If it is lower than the specified limit, you need to add more.
  • Bleed the air from the brake lines: If your brake system has air, you need to bleed it to ensure the efficient operation of your brake system.
  • Replace the faulty ABS: If your ABS is bad, you need to replace it.
  • Replace dirty air filters: Inspect the air filter of your vehicle. If it is dirty or damaged, repair or replace it as soon as possible.
  • Replace Damaged Fuel Injectors: Inspect the fuel injector of your vehicle and replace it if it is damaged.

FAQ Section

Why does my car jerk at high speeds?

If your car is experiencing surging or jerking at high speeds might be a sign that it’s not getting sufficient air-fuel mixture. This jerking can result from issues with various components in the fuel or air intake system, which can also negatively impact fuel efficiency.

Is it dangerous if the car jerks when braking?

Indeed, any situation that causes a loss of control in the vehicle can be hazardous, and experiencing the car jerks while brakes are not applied. It signifies that there is an issue with a part in your vehicle’s braking system. This may be unsafe, as it may lead to an accident.

Does my car jerk due to a clogged air filter?

A clogged air filter can also lead to a decrease in the amount of air supplied to the combustion chamber. This reduction can cause an excess of unburned fuel, which then converts into soot. The soot may build up on the tip of your spark plug, hindering its ability to deliver a strong spark. This can result in the vehicle jerking, having an unstable idle, or even causing the engine to misfire.

Why does the car jerk when accelerating and braking?

One common cause of a jerky accelerator is a clogged fuel injector. When attempting to drive from a stop or maintain a steady speed, your car may lose power due to an engine misfire caused by dirty fuel injectors.

Can a bad transmission cause the car to jerk?

An automatic transmission in a car relies on fluid to shift gears seamlessly. A well-functioning transmission ensures smooth gear transitions in your vehicle. However, if you experience shaking, jerking, or shuddering while shifting gears, it could indicate a low transmission fluid level or the need for a gearbox replacement.

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