Your parking brake - also called the emergency brake or e-brake - is a simple but important system that holds the car still when it is parked. What surprises many people is that it is largely separate from the hydraulic brakes you use to stop.
A separate, mostly mechanical system
When you press the brake pedal, hydraulic fluid does the work. The parking brake instead uses a cable (or on newer cars, a small electric motor) to mechanically apply the rear brakes and lock the wheels. Because it does not rely on hydraulic pressure, it can still hold the car even if the hydraulic system loses pressure - which is part of why it exists.
Drum-in-hat, rear shoes, or caliper
- On many vehicles with rear disc brakes, a small drum brake built into the rotor hub (a drum-in-hat) is what the parking brake applies.
- On rear drum vehicles, the parking brake expands the same brake shoes used for stopping.
- Some rear-disc systems use a mechanism that clamps the caliper.
Why you should use it every time
Using the parking brake takes strain off the transmission's parking pawl - the small part that holds an automatic in Park. On a hill especially, relying on Park alone puts all the load on that one part. The parking brake shares the load and keeps the car from rolling. Regular use also keeps the cables and mechanism from seizing up.
When the parking brake sticks
If a parking brake is left on for a long time, or the cable corrodes, it can stick or freeze - especially in cold, wet climates. Signs include a rear brake that drags, a car that resists moving, or a lever that will not release. Freeing and lubricating or replacing the cable fixes it. If your rear brakes need service, our brake service guide and the correct rear pads or shoes get you sorted. Brakes are safety-critical - if unsure, see a professional.