Skip to main content

Brake Caliper


Brake Caliper is a hydro-mechanical C-shaped assembly that is mounted onto the rotor which stops the wheels from moving. It contains the brake pads, pistons, bleeder screw, piston and seal kit, dust boot, and anti-rattle clips.

Fixed Calipers 

  • Fixed Calipers have at least pistons and are mounted directly to the steering knuckle. Each piston receives equal fluid pressure and pushes on a brake pad. This type of caliper is used mainly in high-performance applications.
  • When the brakes are applied, the brake fluid in the caliper pushes the pistons, forcing them out of their bores and toward the brake disc. Since hydraulic pressure is equal in the system, the force applied by each piston is also equal.
  • The square seal surrounding each piston keeps the fluid sealed in the bore.
  • When the brakes are applied, the seal deforms slightly as the pistons move outward When the brakes are released, the seal returns to its original shape pulling the piston back. This causes the seal to act as a return spring for the piston and allows the disc brake caliper to be self-adjusting. As the brake pads and rotor disc wear, the volume behind the pistons increases.  The brake fluid continues to take up this volume as the pistons move further out as the pads wear,

Floating Calipers

  • Floating Calipers are the most common types of brake caliper used in modern cars and light trucks. 
  • Unlike the fixed caliper, the floating caliper has to be able to move so that both brake pads are applied
  • When the fluid pressure pushes on the back of the caliper piston pushes on the inner pad and the inner pad against the brake
  • As the fluid pushes against the pistons, it also pushes against the caliper piston bore