Parking brakes are often overlooked as a necessity these days, with most cars equipped with automatic transmissions that lock the wheels in place whenever you shift into "park.” However, car manufacturers recommend the use of the parking brake (sometimes called the emergency brake or hand brake) to immobilize any parked vehicle, automatic or manual. Some states require the parking brake to be engaged every time a vehicle is parked. At the very least, cars are required to have an operational parking brake.
How this system works:
Automatic transmissions use a pin called a parking pawl to lock the transmission in place when you shift into “park,” which prevents the wheels from moving. This pin is very small in comparison to the size of the vehicle (it’s about the size of your pinky finger), which is why a parking brake is used to assist the transmission to keep the vehicle stationary.
Manual transmissions must be shifted into either first gear or “reverse” before applying the parking brake. This ensures the vehicle remains stationary without adding stress on the transmission.
Parking brakes can be activated several different ways. The two most common ways are with a hand lever located between the driver’s seat and center console or with a foot pedal located on the far left side of the driver’s footwell.
A steel cable joins the rear brakes with the parking brake lever. The force used to pull the parking brake lever tightens the steel cable, transferring that force to the rear brakes, which engage and hold your car in place.
In cars with disc brakes: The steel cable is attached to a spring lever on the brake caliper, which squeezes the brake pads against the brake rotor.
In cars with drum brakes: The steel cable attaches to a lever, which pushes the brake shoes against the brake drum to hold the vehicle in place.
Common reasons for this to happen:
Worn or broken parking brake cable: Not using your parking brake is a common reason for failure. Even though the parking brake cable is housed in a protective sleeve, with infrequent use, the cable can become corroded and rusted. This can result in cable failure just when you need it the most. Everyday use prevents buildup and keeps the cable in good condition.
Seized parking brake: Another cause for parking brake failure is driving with the parking brake engaged. This will overheat your parking brake, prematurely wearing the brake pads or shoes, and possibly lock up your wheels. It is important to remember to release your parking brake before shifting your vehicle into “drive” or “reverse.”
Broken parking brake lever: The parking brake is a self-locking system. When activated, it is designed to lock in place until you press a button or pull a lever to release it. Over time, the springs inside the parking brake lever can fatigue and break. This failure may prevent your parking brake from releasing or engaging, which may leave your vehicle stuck where it's parked.
Faulty parking brake sensor: One of several sensors that activates the red brake warning light on your dashboard, the parking brake sensor informs you when the parking brake is still engaged. Newer cars also use this sensor to alert the driver with an audible “ding.” When this sensor fails, your brake warning light on your dashboard stays illuminated, even if the parking brake has been released.
What to expect:
A top-rated mobile mechanic will come to your home or office to determine the source and cause of the parking brake failure, and will then provide a detailed inspection report that covers the part of the system that failed and the cost of the necessary repairs.
How it's done:
The mechanic will perform a thorough inspection of your entire parking brake system. This includes checking the integrity of the parking brake cable and adjusting it if necessary. While inspecting the parking brake lever for proper operation, the mechanic will also remove the wheels and check the brake components themselves for wear and damage.
How important is this service?
A parking brake is a required component of every car and must be kept in good operating condition. Moreover, it is important to address any concerns you may have with your parking brake as soon as possible to prevent possible damage to other components of your vehicle, particularly those within your general braking system.