Floating Brake Caliper
A floating brake caliper, also called a sliding caliper, has a caliper body that moves sideways on guides as the brake is applied.
How it clamps the disc
Hydraulic or electromechanical force pushes one or more pistons against the inboard pad. The reaction force slides the caliper body so the outer pad is pulled against the opposite side of the disc. A fixed caliper instead keeps its body stationary and normally uses opposing pistons on both sides.
Floating calipers can provide the required clamp force with fewer pistons and a compact, relatively light housing. Their guides and seals must move freely: contamination, corrosion, or worn guide components can cause drag, noise, or uneven pad wear. The name describes the caliper movement, not a floating brake disc.
An EV can use floating or fixed calipers. Regenerative braking may reduce routine friction-brake use, but it does not change the caliper’s basic role when wheel-brake torque is requested.
For the complete friction-brake system and its interaction with regeneration, see Brake Systems.