Skip the auto shop - Our mechanics make house calls

How the Parking Brake Works

How Parking Brakes Work

A parking brake (also known as an emergency) is part of the vehicle’s braking system. You will see a lever inside the car, often by the center console, which may be engaged when needed. Because of this lever, another term that is also used to describe the system is a handbrake.

What a Parking Brake Does

The original designation for a parking brake was to stop the vehicle if the main brake system should fail, which is why it was known as an emergency brake. In modern vehicles, the emergency brake isn’t very effective at this task because it cannot adequately stop the vehicle with the small amount of force applied. The parking brake is connected to the rear brakes, which do not exert as much force in braking as the front brakes and will do little to stop a vehicle moving at high speeds.

Most modern applications of the parking brake is to ensure that a parked vehicle stays in place, especially on hills and other declines. When engaged, it locks the wheels in place and works with the parking pawl to ensure that the vehicle doesn’t roll away. While a parking brake isn’t required to be engaged for the vehicle to stay stopped, it works to prevent your vehicle from rolling, especially on steep inclines, and to reduce stress on the transmission. This is why manufacturers recommend using the parking brake even when the driver doesn’t feel like he or she needs it.

When a vehicle’s gear shift is put into Park position, a parking pawl is engaged in the transmission. This is a pin that locks the gears into place to prevent them from rotating. The pawl stays in place until the gear shift is moved out of the Park position. The problem with relying on this mechanism for the vehicle is that it puts stress on the transmission constantly, which can result in eventual failure. Manufacturers recommend engaging the parking pawl after using the parking brake. The brake provides additional security and reduces the amount of stress on the transmission and driveline components to prevent costly repairs and parking failure.

Components of a Parking Brake

The typical parking brake has fewer components than the main brake system. They include variations of the following:

  • A lever to engage and disengage the parking brake, found within the cabin of the vehicle
  • Steel cables to connect to the main brakes of the vehicle located in the rear, often called a parking brake equalizer

The cable system features a “Y” design that allows a set of cables to be connected to each rear brake. A separate cable attaches to the equalizer or “Y” connection and the lever inside the vehicle. Often, these cables are contained inside an outer shell or shielded. The lever may have a separate button to deactivate the emergency brake. Some foot pedals require you to depress the foot brake twice to deactivate it.

Types of Parking Brakes

There are four basic types of parking brakes:

  • Stick lever – found in older models and located under the instrument panel
  • Center lever – located between front bucket seats and seen in many newer model vehicles
  • Pedal – located on the floor to the left of the other pedals
  • Electric or push button – located on console with other controls

How the Parking Brake Works with Various Systems

Because not all braking systems are identical, the differences impact how the parking brake works. Vehicles with automatic transmissions often have parking brakes with automatic releases while some later models require the main brake pedal to be depressed before the transmission can be switched out of park. Anytime Drive or Reverse is selected on the automatic transmission, the parking brake is automatically released. Older models would only require the gear shift to be moved without pressing down on the brake pedal.

The parking brake will press against rear drum brakes mechanically with a force that is less than what is used with the main braking system. With disc brakes, the emergency brake activates the calipers or a small drum brake that is contained within the hub of the disc. Larger vehicles often come with power-operated parking brakes or ones that are power assisted. The driver will pull the lever and hydraulic pressure is allowed into the brake cylinder, applying force to the brake shoes. This is an added safety mechanism that is often seen on commercial vehicles.

A recent development in parking brakes is the electric parking brake. It functions much the same way as the traditional parking brake, except that it engages at a push or pull of a button instead of using a mechanical lever. The more advanced designs even use a motor that is controlled by a computer to engage the parking brake. Some high-end luxury models have a system that automatically engages the parking brake when the engine is stopped. It is released once the gas pedal is pressed with no other human intervention necessary.

Issues with the Parking Brake

One of the main issues with the parking brake for owners is corrosion. When the parking brake is not engaged on a regular basis, it begins to corrode. Shielded cables are especially vulnerable because water and road debris gets trapped in the outer shell. You won’t realize there is a problem until you need the brake, which is why regular inspection is important. It is also recommended that you use your parking brake every time you park to keep it in working order.

With regular inspection and maintenance, you may never need to replace your parking brake. You want to ensure it is in good working order in case you must rely on it for any reason.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....

Related questions

Q: How do I use the folding mirrors?

Power folding mirrors are a premium feature on the vehicle, so the only vehicles with the feature will have premium trim. Below the mirror control, there is a switch with two symbols resembling mirrors on either end. The symbols...

Q: Noise when braking

Hi there, thanks for writing in. It seems the anti-lock braking system (ABS) is activating when it should not be. If the ABS detects a sensor at zero when you are driving and hitting the brakes, it will activate the...

Q: Emergency brake not working

Hello. Your Grand Cherokee has a cable-operated hand brake, and is adjustable from under the car. Sometimes, the cables are stretched, and a spacer will need to be installed on the threaded adjuster to get the proper tension. Check your...