How Does the Parking Brake Work?
March 20, 2019
BY MATTHEW C. KEEGAN / ORIGINALLY PUBLISHED MARCH 18, 2018 / NATIONAL AUTOMOTIVE PARTS ASSOCIATION /
When finishing a trip, you place the transmission in park, turn off the ignition and take your keys with you before exiting the vehicle. But there is another step you should include: engage the parking brake. The parking brake supplies an extra measure of insurance when your vehicle is stopped. We’ll answer, “how does the parking brake work?” and explain the potential consequences of not using one.
The Purpose of a Parking Brake
A parking brake is sometimes known as an emergency brake and is typically designed as a hand- or foot-controlled lever in most vehicles. In some modern vehicles, the parking brake is switch operated and may automatically engage when the transmission is in park. Regardless, once engaged, the parking brake is tasked with keeping the vehicle stationary. Under most circumstances, it isn’t enough to expect your vehicle to not move — a bump from another vehicle or a tremendous gust of wind could send it rolling. Engaging the parking brake can prevent that from happening.
The parking brake system consists of steel cables, which supply force to keep the vehicle immobile. When the handbrake is pulled or the brake pedal pushed, the cables tighten. Rear parking brake shoes, which operate separately from the main braking system, secure the rear wheels by squeezing the inside of the drum, holding the car in place. As you might guess, the parking brake should be a part of your routine brake maintenance work.
A parking brake may also serve as an emergency brake when your main braking system fails. Thus, if you apply pressure to your brakes while driving and the car doesn’t stop, you can engage the parking brake to slow the vehicle. Automotive manufacturers typically don’t refer to it as an emergency brake, because full stoppage isn’t a guarantee.
Parking on a Hill
We may not think about engaging the parking brake when stopped on a flat surface, but that will certainly change once we’re parked on a hill. Once engaged, the parking brake can keep your car from rolling down the hill and creating destruction in its path.
If you’re parking uphill (where the road is rising) and a curb is present, point the front wheels away from the curb. If there is no curb, then point the wheels to the right. Even with the parking brake engaged, either action ensures your vehicle won’t roll into traffic if it is bumped while parked.
On the other hand, if you’re parking downhill (where the road is dropping), always turn the front wheels to the right whether a curb is present or not. In all three examples, either the curb will stop the vehicle from rolling into traffic and risking further destruction or it will roll off the road where it is less likely to do major damage.
Engage the Parking Brake
When coming to a complete stop, immediately engage the parking brake before placing your car in park. That way, the pressure is off of the transmission, reducing wear and tear. When you’re ready to move again, press your main brake, release the emergency brake and then place the transmission in drive.
By answering the question of “how does the parking brake work,” you’ll see why engaging your vehicle’s parking brake when you’ve completed a trip is a good habit to get into. Not only will your car’s parking brake ensure that your car will remain stationary, but it can also be used in case of an emergency.
Check out all of the brake system parts available on NAPA Online or trust one of their 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on how your parking brake works, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photos courtesy of Matthew C. Keegan.
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