Brake Release

As the brake pedal is released, hydraulic pressure in the brake caliper housing collapses and force is no longer applied to the brake pads. The brake pads are moved slightly outwards by the action of the rotating brake disc, and the brake caliper internal annular seal returns to the normal shape. As the seal moves, it grips on the piston outer surface and withdraws the piston into the housing to provide the necessary brake pad to brake disc clearance.

This action prevents the piston from holding the inner brake pad against the brake disc. It also enables the piston to protrude further from the brake caliper housing to compensate for brake pad wear.

With no pressure applied to the hydraulic system, the housing spring tension is also relieved and the spring returns to the normal position. As the housing spring moves, the attached sliding brake caliper is moved away from the outer side of the disc. This action provides the necessary clearance between the outer brake pad and the brake disc.