Conmet Conventional, Service Manual

Page: 53 / 76

49 ConMet
10. Hub and Rotor Inspection (continued)
56
106858a
Grease-Stained Rotor
FIGURE 114
Lining Transfer
High operating temperatures
or improper lining material can
result in brake lining transfer
onto the braking surface of the
brake rotor (see figure 115). This
may start as a spotty thin layer of
lining material that has become
welded to the brake rotor and
may end up covering most of the
braking surface. This condition will
accelerate lining wear.
The buildup can be removed by
resurfacing the brake rotor. Rotors
should not be resurfaced to less
than 0.060" above the minimum
allowable thickness to allow for
wear. The cause of the high brake
operating temperature should be
identified and corrected before the
vehicle is put back into service.
57
106841a
Lining Transfer
FIGURE 115
Clogged or Restricted
Vent Holes
Off-road and severe-duty
applications may result in vent
holes in the rotor becoming
blocked by an accumulation of
debris such as rocks or dirt (see
figure 116). The vent holes should
be cleaned as required to allow
air flow and proper cooling of the
brake rotor.
58
106859a
Clogged Vent Holes
FIGURE 116
Rotor Runout
Lateral runout, or wobble, on the
rotor braking surface should not
exceed 0.020" in one full revolution
of the rotor. The measurement
should be taken with a dial
indicator at the center of the rotor
braking surface. See figure 117 for
proper runout measurement set up.
The runout measurement should
not include end play of the
wheel bearings. If the runout
measurement is over 0.020", the
end play of the wheel bearings
should be checked. If the wheel
bearing end play is greater than the
manufacturer's recommendations,
the wheel bearings should be
adjusted per the manufacturer's
recommendations.
Radial runout on the outside
diameter of the braking surface
should not exceed 0.035" when
checked with a dial indicator
(see figure 118). If the runout
exceeds 0.035", the rotor should be
replaced.
59
106842a
CENTER OF
ROTOR BRAKING
SURFACE
Lateral Runout
FIGURE 117
60
106843a
OUTSIDE
DIAMETER
OF ROTOR
Radial Runout
FIGURE 118
Rotor Thickness
The rotor thickness should be
measured at three points using a
micrometer as shown in figures
119, 120 and 121. If the rotor
thickness varies more than 0.005"
between any two places, the rotor
should be replaced.
61
106865a
TOP OF
ROTOR
Top of Rotor
FIGURE 119