Calipers are “floating” design. A floating caliper, common on production vehicles, has a piston or pistons only on the inboard side of the caliper. The floating caliper is mounted on pins or slides so that when the piston extends and presses the inboard pad against the rotor, the whole body of the caliper slides on its pins or guides in the opposite direction, bringing the outboard pad into contact with the rotor.
Here is the advantage of a floating caliper:
- Floating calipers are smaller, lighter, and easier to package. They are also cheap, readily available, and easy to mount.
- Floating calipers cool better as the fluid and piston are only on the inboard side of the rotor.
- Floating calipers have fewer moving parts and seals to leak or wear out.
- Floating caliper design more easily incorporates a cable-operated parking brake.
Operation of a Floating Caliper
When brakes are applied, piston on outboard side extends in direction of red arrow until outboard pad contacts rotor. At that point, caliper slides on pins in direction of blue arrows until inboard side of caliper presses inboard pad against rotor.