Meritor MM-2075 Maintenance Manual page 21

Figure 7.3
Heavy Heat Checking
Heavy heat checking is surface cracks that have width and depth.
Replace the rotor if the heat checks have a width greater than
0.02-inch (0.5 mm), depth greater than 0.04-inch (1 mm) and
extend across the surface more than 75% in the radial direction.
Figure 7.4.
Figure 7.4
Deep Grooves or Scores
Inspect both sides of the rotor. If you find grooves or scores of a
depth less than 0.02-inch (0.5 mm), continue to use the rotor. If
the grooves are greater than 0.02-inch (0.5 mm), you may choose
to resurface the rotor. If the rotor thickness measured across any
groove is less than the minimum discard thickness found on the
rotor casting, discard and replace the rotor. Figure 7.5.
(16579)
Printed in USA
4005053a
MAXIMUM
LENGTH = 75%
4005052a
Copyright Meritor, Inc., 2023
Figure 7.5
Blue Marks or Bands
Blue marks or bands indicate that the rotor was very hot.
Determine the cause and correct the conditions. Figure 7.6.
Figure 7.6
7 Rotor
4001601a
4001602a
MM-2075 / Revised 09-23
Page 17