What if I accidentally drove with the parking brake on?

It happens to the best of us. In the hustle and bustle of everyday life, it's entirely possible to mistakenly drive off with your parking brake still engaged. While it might seem like a minor oversight, continuing to drive with the parking brake on can have significant consequences for your vehicle. Understanding what happens, the potential damage, and what to do next is crucial for any car owner.

What Exactly Happens When You Drive With the Parking Brake On?

The parking brake, also known as the emergency brake or handbrake, is designed to keep your vehicle stationary when parked. When engaged, it typically applies a mechanism that directly actuates the rear brakes, often through cables. This mechanism is separate from your primary hydraulic braking system.

When you drive with it on, you're essentially dragging the rear wheels against this engaged braking force. This creates:

Increased Friction and Heat: The primary effect is immense friction between the brake pads and rotors (or brake drums), generating excessive heat.
Resistance to Motion: Your engine has to work much harder to overcome the drag from the engaged parking brake, leading to reduced acceleration and fuel economy.
Uneven Braking Force: Because it's usually applied to the rear wheels, you'll experience a noticeable pulling sensation or uneven braking if you try to stop.

How Far Did You Drive? The Impact of Distance

The severity of the damage directly correlates with how long and how far you drove with the parking brake engaged. Even a short distance can cause minor issues, while longer distances can lead to costly repairs.

A Few Feet or Seconds: If you realized your mistake almost immediately and only moved a very short distance, the damage might be minimal. You might notice a burning smell or some slight discoloration on your brake components.
A Few Blocks or Minutes: Driving for a few blocks or several minutes will likely cause more significant heat buildup. This can lead to warping of the brake rotors and premature wear on the brake pads. You might also start to notice a decrease in braking effectiveness.
Miles or Extended Driving: Driving for several miles with the parking brake on can cause severe damage. This can include:
- Warped Brake Rotors: The extreme heat can cause the metal rotors to deform, leading to pulsating sensations when you brake and reduced stopping power.
- Burned or Glazed Brake Pads: The friction material on the brake pads can overheat, become glazed (hardened and less effective), or even burn away.
- Damaged Calipers or Wheel Cylinders: The heat can affect other components of the braking system, such as the calipers (which hold the brake pads) or wheel cylinders (in drum brake systems).
- Stretched or Damaged Parking Brake Cables: The cables that actuate the parking brake can stretch, weaken, or even break under prolonged tension and heat.
- Tire Damage: In extreme cases, the heat generated can even affect the tires, though this is less common.
- Overheated Wheel Bearings: The excess heat can also transfer to the wheel bearings, potentially causing them to fail prematurely.

What are the Signs You've Driven with the Parking Brake On?

If you suspect you've made this mistake, pay attention to the following signs:

Burning Smell: A distinct acrid or burning smell, often described as "burning rubber" or "burning oil," is a common indicator of overheated brakes.
Reduced Braking Performance: Your brakes might feel less responsive, or you might notice a pulsating sensation in the brake pedal when you try to stop.
Pulling to One Side: If the parking brake is unevenly applied or one side is more affected, your car might pull to one side when you brake or even when driving straight.
Visible Smoke: In severe cases, you might see wisps of smoke coming from the rear wheels.
Warning Lights: Some vehicles have a parking brake warning light that might stay illuminated or flicker.
Unusual Noises: You might hear grinding or squealing noises from the rear of the vehicle.

What Should You Do If You Accidentally Drove with the Parking Brake On?

If you realize you've driven with the parking brake on, the most important thing is to act quickly and safely:

Pull Over Immediately and Safely: Find a safe place to stop your vehicle as soon as you realize the mistake. Do not continue driving.
Engage the Parking Brake Properly (if it wasn't fully engaged): If you only partially engaged it and it was dragging, ensure it's either fully released or fully engaged and functional once you've stopped.
Let the Brakes Cool Down: Allow the brakes to cool completely. This can take several hours. Do not touch the brake components as they will be extremely hot.
Inspect Your Brakes: Once cooled, visually inspect the rear wheels and brake components for any signs of damage, such as discoloration, warping, or melted material. Check for any loose or damaged cables.
Check Your Tires: Ensure your tires haven't been affected by the heat.
Get Your Brakes Inspected by a Professional: Even if there are no obvious signs of damage, it is highly recommended to have your braking system inspected by a qualified mechanic. They can check for internal damage, warped rotors, damaged pads, and the integrity of the parking brake cables.

Can You Drive with the Parking Brake On for a Little Bit?

It's generally not advisable to drive with the parking brake engaged for any significant distance or time. While a very short, slow movement might not cause major issues, it's still a risk. The components are not designed for this kind of continuous stress and heat.

What's the Difference Between the Parking Brake and Regular Brakes?

Your regular brakes (foot brakes) are hydraulic and apply force to all four wheels, providing the primary stopping power for your vehicle. The parking brake, on the other hand, is typically mechanical, usually only acting on the rear wheels, and is intended for parking and as an emergency backup.

Will My Car Be Okay?

Whether your car will be "okay" depends entirely on how long and how far you drove with the parking brake on. A few seconds or feet might result in no lasting damage, while miles of driving could necessitate significant brake repairs.

FAQ Section

How to prevent driving with the parking brake on?

The best way to prevent this is to develop a routine. Make it a habit to always check that the parking brake is fully disengaged before you start driving. Many cars have a visible indicator light on the dashboard that illuminates when the parking brake is engaged, so be mindful of that.

Why does the parking brake make a burning smell?

The burning smell is caused by extreme friction and heat generated as the brake pads and rotors (or drums) are forced together while the car is moving. The friction material on the brake pads, as well as the metal components, can overheat and burn, releasing that distinct odor.

What kind of damage can happen to the parking brake cable?

Driving with the parking brake on can cause the parking brake cables to stretch, weaken, or even break. The continuous tension and heat can degrade the materials, leading to the parking brake not holding effectively or becoming inoperable.