The parking brake, often referred to as the emergency brake, is critical for keeping a vehicle stationary when parked, especially on an inclined surface. Fewer cars have manual transmissions these days, but it's easier for a manual vehicle to roll away than an automatic, unless the parking brake is applied. However, parking brake use is also important with automatic transmissions to avoid wear and tear on internal parts. It's a good habit to engage the parking brake no matter what kind of vehicle or transmission you have, and to make sure it's in good working order.
The parking brake has historically been a fail-safe mechanical system, separate from the hydraulic brakes. Despite the introduction of new braking technology over the years, for a long time the parking brake remained relatively low-tech on most vehicles. There's a mechanical lever or pedal inside the car, typically connected to the rear brakes (usually disc brakes these days) via steel cables, to manually engage the parking brake. However, the parking brake on today's vehicles has become more sophisticated, for a variety of reasons that include streamlined design and human forgetfulness.
Jovan M/Shutterstock
The electronic parking brake first arrived in the early 2000s, notably in the 2001 BMW E65 7-Series. BMW's Electro-mechanical Parking Brake system included an electronic switch on the instrument panel to activate the parking brake. The switch controlled an actuator module mounted at the rear of the vehicle. The module would interpret the signal and activate a motor to engage or release the parking brake. The motor was connected to the mechanical parking brake at the rear wheels via traditional cables. The system operated as both a parking brake or an emergency brake, depending on conditions. The parking brake was applied fully when the vehicle was stationary, or dynamically to decelerate the vehicle while driving.
Twenty-five years later, electronic parking brakes are commonplace in new vehicles. Newer systems are fully electronic, featuring electric actuators mounted directly on the brake calipers. This eliminates common problems with mechanical parking brakes, including malfunctioning and seizing up over time, or cables stretching and fraying with regular use. Exposure to the elements could also cause mechanical parts to rust and seize up, rendering the parking brake inoperable.
An electronic parking brake switch makes interior placement more flexible, and elimination of cables along the undercarriage also frees up space. For driver ease of use, pressing or pulling a switch eliminates the physical force needed to apply the parking brake. An additional auto hold feature can help keep the vehicle from rolling back on a hill while at a stop. An electronic parking brake can also provide customizable user settings, or operate automatically under certain conditions. No more forgetting to set the parking brake, or worse, not fully releasing it.
