The parking brake, often referred to as the handbrake or emergency brake, is frequently misunderstood by drivers of automatic transmission vehicles. Many assume that placing the gear selector in “Park” (P) is sufficient for securing the car, especially on flat surfaces. This leads to the parking brake being viewed only as an emergency measure or a tool for steep inclines. Understanding how an automatic car is secured reveals that the parking brake is a functional part of routine vehicle operation and safety. Using it regularly helps protect the vehicle’s transmission components from unnecessary wear and strain.
Understanding the Difference Between Park and the Parking Brake
The common practice of relying solely on the “Park” gear overlooks the actual mechanism inside the transmission. When the gear selector is moved to “P,” a small, hardened metal pin known as the parking pawl is deployed. This pawl engages a notched wheel within the transmission, physically locking the drivetrain and preventing the wheels from turning.
This locking mechanism is relatively small and vulnerable to stress, particularly on a slope. When the vehicle’s entire weight rests on the pawl, the immense force strains the transmission components. This strain is why the vehicle can be difficult to shift out of “P” when parked on a hill.
The parking brake operates on an entirely different principle, providing a robust and independent method of securing the vehicle. This system mechanically engages the rear brakes, either through cables or via electronic motors in modern systems. The force applied is directly to the wheels, bypassing the transmission entirely.
The parking brake distributes the holding force across the wheel assemblies using the vehicle’s braking system. This mechanical engagement ensures the car’s weight is restrained by the brakes, not a small pin inside the gearbox. Engaging the parking brake before shifting into “P” ensures the vehicle’s weight settles onto the brake pads or shoes first, relieving the pawl of the primary holding duty.
Essential Scenarios for Parking Brake Use
Using the parking brake should be integrated into the standard practice for nearly every parking situation. On flat ground, consistent use prevents repetitive stress that accumulates on the transmission pawl over time. While the pawl may hold the vehicle, the constant tension accelerates the wear of internal transmission parts.
The necessity of the parking brake is clearer when parking on any incline or decline. When gravity pulls the car, the transmission pawl alone bears a substantial load. Engaging the parking brake first securely holds the vehicle, ensuring the pawl acts only as a secondary safeguard.
The parking brake also has applications during maintenance and stationary periods. When the car is running but stationary, such as checking fluid levels or waiting in traffic, engaging the parking brake offers added safety. This prevents accidental movement if the driver’s foot slips from the brake pedal.
The system functions as a backup if the primary hydraulic braking system fails. If the main brakes fail, the parking brake can be used cautiously to slow the vehicle. The technique involves slow, steady engagement, as sudden activation at speed can cause the rear wheels to lock up, leading to a loss of control.
The brake is also useful when the vehicle is jacked up for maintenance, such as changing a flat tire. Engaging the parking brake on the wheels that remain on the ground prevents unwanted rolling or shifting during the jacking process. This action improves stability and safety.
The Correct Parking Procedure
To ensure the vehicle’s weight is supported by the parking brake and not the transmission pawl, a specific sequence should be followed every time the car is parked. This procedure shifts the mechanical burden from the gearbox to the dedicated braking system. The first step involves bringing the vehicle to a complete stop using the foot brake.
Once stopped, shift the gear selector into Neutral (N) while keeping the foot brake depressed. Neutral disengages the transmission, allowing the car to roll slightly before the parking pawl is engaged. Then, firmly engage the parking brake by pulling the lever or pressing the button.
After the parking brake is set, slightly release the foot brake. This allows the car to gently settle back a few millimeters, transferring its weight onto the engaged parking brake components. This settling movement confirms the brake is taking the full load.
The next step is to re-engage the foot brake and shift the gear selector from Neutral into Park (P). The parking pawl engages the notched wheel, but since the car’s movement is already arrested by the parking brake, the pawl is under minimal tension. The engine can then be turned off.
For drivers with modern electronic parking brakes (EPBs), the principle remains the same. Following the manual sequence of Neutral, EPB engagement, and then Park is the recommended practice for protecting the transmission. To release the car, the reverse order is used: shift from P to N, release the parking brake, and then shift into Drive or Reverse.