Rotor Removal
To remove the rotor, remove the caliper as explained
earlier in this chapter. Some rotors are held in place by
screw or bolt fasteners, or the wheel nuts when the tire and
rim are installed. Most can be taken off the hub once the
rim and caliper are removed. Other rotors are integral (part
of the hub assembly), and the wheel bearings must be
removed to remove the rotor, Figure 13-28. To remove
these rotors, remove the dust cap and cotter pin holding
the spindle nut in place. Remove the nut and pull the rotor
and hub assembly from the vehicle. Be careful not to dam-
age any bearing parts during removal. On some vehicles,
you may have to remove a caliper mounting bracket or
other components to remove the rotor.
Turning Rotors
The rotor can be turned on or off the vehicle, depend-
ing on the type of rotor installation, and the lathe available.
On late-model vehicles, some manufacturers recommend
the rotors be turned on the vehicle.
Chapter 13 Disc Brake Service 221
Note: Some front-wheel drive vehicles
require a puller to remove the hub before
the rotor can be removed. Unless the rotor
is to be replaced, determine if the rotor needs
machining or use an on-car brake lathe.
Figure 13-26. Measuring a brake rotor. A—The micrometer is
placed on the rotor. B—Measure at 4 to12 spots around the
rotor for the most accurate reading. C—Side view of a brake
rotor illustrating uneven wear of the braking surface.
(TRW, Inc. & Wagner)
neven wear on Un
raking surface br
Measuring M
point
Rotor
Measuring parallelism at 4 to 12
points around the motor
Excessive
thickness
variation variation
Rotor
Rotor
micrometer
Figure 13-27. r Using a dial indicator to check the rotor for
lateral runout.
A
B
C