Rear Disc Brake Rotor (4 4 Model); Inspection; Replacing Brake Rotors; Refinishing Brake Rotors - Isuzu 1999 RODEO Workshop Manual

5C–46 POWER–ASSISTED BRAKE SYSTEM

Inspection

In the manufacturing of the brake rotor, all the tolerances
regarding surface finish, parallelism and lateral runout are
held very closely. Maintaining these tolerances provides
the surface necessary to assure smooth brake operation.
Lateral Runout
Lateral runout is the movement of the rotor from side to
side as it rotates on the spindle. This could also be
referred to as "rotor wobble".
This movement causes the piston to be knocked back into
its bore. This results in additional pedal travel and a
vibration during braking.
Checking Lateral Runout
1. Adjust the wheel bearing correctly, referring to
"Differential" in Section 4A.
2. Attach a dial indicator to some portion of the
suspension so that the stem contacts the rotor face
about 29 mm (1.14 in) from the rotor edge.
3. Move the rotor one complete rotation.
1. The lateral runout should not exceed 0.13 mm
(0.005 in)
Maximum runout: 0.13 mm (0.005 in)

Rear Disc Brake Rotor (4 4 Model)

411RS019
Parallelism
Parallelism is the measurement of thickness of the rotor
at four or more points around the circumference of the
rotor. All measurement must be made at 22 mm (0.87 in)
from the edge of the rotor.
The rotor thickness must not vary more than 0.010 mm
(0.0004 in) from point to point.
Maximum parallelism: 0.010 mm (0.0004 in)

Replacing Brake Rotors

When installing new brake rotors, do not refinish the
surfaces. These parts are at the correct level of surface
finish.

Refinishing Brake Rotors

Accurate control of the rotor tolerances is necessary for
proper performance of the disc brakes. Machining of the
rotor should be done only with precision equipment. All
brake rotors have a minimum thickness dimension cast
into them. This dimension is the minimum wear
dimension and not a refinish dimension. The minimum
wear dimension is 16.6 mm (0.654 in). The minimum
refinish dimension is 16.97 mm (0.668 in).
When refinishing rotors, always use sharp cutting tools or
bits. Dull or worn tools leave a poor surface finish which
will affect initial braking
dampening attachments should always be used when
refinishing braking surfaces.
eliminate tool chatter and will result in better surface
finish.
After refinishing, replace any rotor that does not meet the
minimum thickness of 16.97 mm (0.668 in). Do not use a
brake rotor that will not meet the specification.
Minimum wear dimension: 16.6 mm (0.654 in)
Refinish dimension: 16.97 mm (0.668 in)
420RS013
performance. Vibration
These attachments