When it first came out, the parking brake served as the emergency backup to the main brakes. Nowadays, it teams up with the parking gear to make sure your vehicle doesn’t budge from its parking spot, especially when you have to leave it on an inclined slope. To better understand how this still-important system works, read on.
What Is a Parking Brake?
The parking brake is a latching mechanism that is a part of the overall brake system but operates independently and not through the hydraulics of the primary braking system. The parking brake connects to the rear wheels and the rear brakes.
Whereas most main brake systems rely on hydraulic pressure to operate their moving parts, the typical parking brake relies on mechanical cables to engage and disengage the brakes. By using a different method of operation, the emergency parking brake will keep working even if the main brakes develop a hydraulic-related issue that causes the latter to act up or fail.
Some manufacturers also offer electronic parking brakes. Instead of cables, these parking brakes use geared electric motors. You engage or disengage the electronic parking brake by pushing a single button that takes up far less room than a control lever or pedal.
During its first appearance, the parking brake was called the emergency brake or e-brake for short. Other people used the term emergency parking brake. Some people called it the hand brake because they operated it by hand through a lever.
What Does the Parking Brake Do?
The parking brake makes sure your vehicle doesn’t budge while it’s parked. It’s critical when you park on road surfaces that aren’t level, such as roads that go up and down inclines.
In automatic vehicles, the parking brake works with the parking gear. When you shift to parking gear, the transmission engages a pin called the parking pawl to lock its gears in position. However, the pawl can break from the constant stress placed on it by the heavy gears.
By engaging the emergency parking brake and the parking gear together, you take some of that strain off the parking pawl. That makes the pawl last longer.
The right way to park your vehicle is to engage the parking brake first and then shift the transmission gear to the park position. When you’re ready to leave the parking spot, switch to the appropriate gear and then disengage the brake.
How Does A Parking Brake Work?
The parking brake attaches to the rear brakes through a series of cables arranged in a Y-shaped pattern. Because it uses mechanical means to engage and disengage the brakes, the emergency brake doesn’t have to rely on hydraulics like the main brakes.
With Drum Brakes
Drum brakes are more common in older vehicles, but some new vehicles use them in the rear. In these vehicles, the parking brake cables directly hook up to the brake shoes inside the brake drum.
When you engage the emergency brake, its cables pull the shoes into the surface of the brake drum’s interior. The contact between the shoes and the drum produces friction that slows down the wheel to which the brake is attached.
With Disc Brakes
Many newer vehicles, especially higher-end models and trims, use more efficient but costlier disc brakes on all four wheels. Their parking brake systems follow one of two configuration styles.
Some four-wheel drive (4WD) vehicles made by Honda and certain other manufacturers feature caliper pistons on their rear wheels. The cables physically connect to these pistons. This parking brake system also shows up in non-4WD drives.
When you engage the emergency brake, the parking brake cables push the brake piston into the brake pads. The force applied by the cable-powered piston presses the pads into the brake rotors, albeit with less power than the hydraulic-powered main brakes.
Other disc brake-equipped vehicles feature a small brake drum inside the brake rotors of their rear wheels. In their case, moving the parking brake lever into the engaged position will press the brake shoes into the internal drum. Much like conventional drum brakes, this will prevent the wheels from rotating.
Types of Parking Brake
While all parking brakes use cables, they can have different ways to engage and disengage the emergency brake. Here are the different types of parking brake systems:
Stick Lever Parking Brake
The stick lever parking brake is the earliest type of emergency brake. Understandably, it mainly appears in older vehicle models.
It takes its name from the slender control lever that engages and disengages the parking brake. You can find the lever under the instrument panel or the steering wheel.
Center Lever Parking Brake
The most common type of parking brake in modern vehicles, the center lever parking brake can be found in numerous models and is likely the one you know. It features a sizable lever located between the front seats, earning its name. There is a prominent button on the lever’s handle.
Engaging this type of parking brake requires you pull the lever up. Releasing the brake involves pushing the button while returning the lever to its starting position.
Pedal Parking Brake
You control the pedal parking brake with a foot pedal. There is also a parking brake lever that you operate by hand.
The parking brake pedal sits to the left of the gas and brake pedals. By keeping the control pedals as far apart as possible, there is minimal risk of accidentally stepping on the wrong pedal.
There are two ways to disengage the pedal parking brake. You can press the control pedal down with your foot. Alternatively, you can manipulate the control lever to pull the release cable. Either way, the pedal parking brake will release the rear wheels, allowing your vehicle to move.
There are two ways to disengage the pedal parking brake. You can press the control pedal down with your foot. Alternatively, you can manipulate the control lever to pull the release cable.
– Anthony Harlin, ASE Certified Master Automobile Technician
Electric/Electronic/Push Button Parking Brake
The newest type of parking brake lets you engage and release the brakes by simply pushing a button. It sees use in recently released models, including many hybrid and pure electric vehicles (EVs). Electronic parking brakes usually use a motor controlled by the car’s computer to engage the brake caliper.
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