• How to Use a Disc Brake Piston Tool

    A disc brake piston tool is great to have when doing your own brake work. Over time, as your brake pads and brake rotors wear, the brake piston in your caliper will move farther and farther out of its bore. This helps maintain the braking function, feel and effort as parts wear down.

    When it comes time to replace your brake pads and rotors, the brake piston must be pushed back into its bore before the new pads and rotors will fit. This is where the disc brake piston tool comes in. It allows you to easily exert a large enough force on the brake piston, to push it back into its bore.

    Using a disc brake piston tool is easy:

    • Remove the brake caliper from the wheel knuckle that it’s mounted to. Be sure to support it on something or with a wire hanger so that the brake hose doesn’t get damaged.
    • Remove the outer brake pad but leave the one on the piston side attached.
    • Retract the screw on your disc brake piston tool and slide its plate into place where the outer pad used to be, lining the retracted screw up with where the piston is behind the other pad.
    • Use the attached handle to screw the screw part of the tool towards the pad. As you do this, you will see the piston-side pad begin to retract.
    • Do this until the pad is flush with the caliper, ensuring the piston is fully retracted.
    • Remove your disc brake piston tool and the piston-side pad.

    Once the caliper has been retracted back into its bore, you can move on to installing your new brake pads and rotors, which will now easily slide over each other. Be sure to press the brake pedal a few times before moving the car, to re-seat the pads against the rotors.