What is an emergency brake cable?
In most vehicles the parking brake, also called the emergency brake, uses a cable connected to the rear brakes to manually set the brakes when the vehicle is not occupied. The parking brake cable and parking brake lever, found near the driver's seat, work in unison to hold the brakes until they are released by the driver.
How does the emergency brake cable work?
The parking brake cable is held in a fixed position, and when the parking brake lever is pulled, pressed, or electronically engaged, the cable is pulled tight. For disc brake systems, this tension presses the rear brakes pads into the rear brake rotor, or, for drum brakes, the rear brake shoes will be pressed into the rear brake drum. Many modern vehicles with rear disc brakes have an auxiliary drum brake inside the brake rotor that is actuated by the cable. This protects the service brakes if the parking brake is left engaged while driving.
What are the symptoms related to a bad emergency brake cable?
When setting the parking brake does not result in the wheels fully locking, the lever may be far easier to press or pull than normal. You may notice the vehicle tries to roll, and is caught by the transmission. This is particularly dangerous for manual transmission vehicles, as the transmission does not have a secondary lock, and the weight of the vehicle may allow it to roll, even if the gear selector is placed in a forward or reverse gear. Vehicles with electronically actuated parking brakes may display a warning on the drivers information center, alerting to the danger of the failed parking brake. Lastly, the parking lever can fail to return to the disengaged position after being released. In this situation the lever will exhibit a total loss of tension, but may provide resistance if manually pressed or pulled into the disengaged position.
Can I drive with a emergency brake cable problem?