198 Auto Brakes
Figure 12-10. One type of floating caliper and anchor plate
showing the machined ways. (Ford)
Machined
ways
Machined
ways
Caliper
housing
Anchor
plate
Key retaining
screw
Caliper
support key
Caliper
support spring
Anti-rattle
spring
Figure 12-9. Two styles of floating (sliding) caliper brake assemblies. A—One piston setup. B—Two-piston arrangement. Compare
both. (Nissan, Toyota)
Bleeder screw
Dust boot
Sliding
bushing
Dust boot
Torque
plate
Dust boot
Dust boot
Brake
caliper
Sliding
bushing
A
B
Bleed
screw
Mounting
bolts
Caliper body
Mounting
bolts
Silicone grease
on pins
Pin
boots
Caliper bracket
The caliper then “floats” inward, bringing the outer brake
pad into contact with the rotor. Pad pressure is then equal
on both sides, which slows the rotor.
When the brakes are released, the outer seal returns
the piston to its normal position. This movement is very
slight as it is done by the seal trying to straighten itself,
which tends to draw the piston in. As the piston returns to
its unapplied position, the pads are moved away from the
rotor. The loss of pad pressure allows the pads and caliper
to “float” back to the normal resting position. This action is
shown in Figure 12-16.
Fixed Calipers
The fixed caliper is rigidly bolted to the spindle and
does not move during braking. Basic fixed caliper opera-
tion is different since hydraulic pistons are installed on
both sides of the rotor.