Caliper & Support
There are two main types of calipers: Floating
calipers and fixed calipers. There are other configurations but these are the
most popular. Calipers must be rebuilt or replaced if they show signs of
leaking brake fluid.
Single Piston Floating Calipers are the most popular and
also least costly to manufacture and service. A floating caliper "floats" or
moves in a track in its support so that it can center itself over the rotor. As
you apply brake pressure, the hydraulic fluid pushes in two directions. It
forces the piston against the inner pad, which in turn pushes against the rotor.
It also pushes the caliper in the opposite direction against the outer pad,
pressing it against the other side of the rotor. Floating calipers are also
available on some vehicles with two pistons mounted on the same side. Two piston
floating calipers are found on more expensive cars and can provide an improved
Six Piston Fixed Calipers are mounted
rigidly to the support and are not allowed to move. Instead, there are three
pistons on each side that press the pads against the rotor. Six piston
calipers have a better feel and are more efficient, but are more expensive to
produce and cost more to service. This type of caliper is usually found on
more expensive luxury and high performance cars.