Electric parking brakes are no longer exclusive to luxury brands. Now many makes and models have an electric parking brake system. Electric parking brake systems are becoming more and more popular. That means more car owners are having a little trouble changing their rear brake pads.
Why Some Electric Parking Brake Systems Make It Hard To Replace The Rear Brake Pads
There are two types of electric parking brake systems:
- Electric motor: Found in some GM vehicles, this electric parking brake system uses an electric motor. It works like a traditional parking brake system, except the motor pulls the parking brake cable instead of a human hand or foot. The motor is called a parking brake control module. When activated, it pulls the parking brake shoes via the parking brake cable.
- Parking brake actuator: You can find this system in non-GM vehicles with an electric parking brake system. Mounted on both rear brake calipers are parking brake actuators. Each parking brake actuator connects to a gear that can force out the caliper piston. When activated, the parking brake actuator can turn that gear. When that happens, the piston pushes the brake pads against the rotor. In other words, this system enables the rear brake pads to act as the parking brake when activated.
On many vehicles with electric parking brakes, the parking brake is activated every time the car is put into park, even if the driver doesn’t push the parking brake switch. To put new brake pads on the rear brakes, you need to disable the electric parking brake first.
Why You Need To Disable The Electric Parking Brake Before Replacing The Rear Brake Pads
Before replacing the rear brake pads, you must disable the electric parking brake. Why is that?
The electric parking brake system uses the brake pads and rotors in the braking system. It has control over the caliper pistons. To remove the rear brake pads, you need to compress the caliper piston first. You won’t be able to do this if parking brake is set. You would be “fighting” with the actuators to compress the pistons.
If you try to compress the pistons while the actuators are pushing them out, you may cause damage. To be more specific, you might damage the actuators and/or the caliper piston mechanism.
Luckily, there’s an easy way to prevent this from happening. You only need to disable the electric parking brake before changing the rear brake pads. Doing so will switch off the actuators.
To disable the electric parking brake, you need to activate the parking brake service mode.
Activating The Parking Brake Service Mode
When the electric parking brake system enters “service mode”, it switches off. In other words, the actuator motors stop applying pressure to the caliper pistons.
There’s no universal way to activate the parking brake service mode. Each make and model has its own procedure. Depending on your make and model, you may need to either:
- Push a series of buttons
- Use the infotainment screen
To find out how to activate the parking brake service mode, check your owners manual or service manual.
When you’re done servicing the rear brakes, don’t forget to reactivate the electric parking brake system!