What should we do with this rotor? Cut it. The rotor needs to be cut because it measured out side of tolerance in both Parallelism & Rotor Runout. Once we are finished cutting the rotor we should measure the overall thickness to make sure we are above the discard thickness of 0.980^n Replace it. The rotor is so far out of spec that we should not waste time cutting it. square rotor thickness - 2(runout measurement;) - 2(finish pass cut depth)=below discard thickness 1.038-2(.0045)-2(.002)=1.025

Based on the information provided, it seems that the rotor is out of tolerance in both parallelism and rotor runout. Therefore, the best course of action would be to replace the rotor rather than cut it.<br /><br />The calculation for the rotor thickness after cutting is as follows:<br /><br />Rotor thickness - 2(runout measurement) - 2(finish pass cut depth) = below discard thickness<br /><br />1.038 - 2(.0045) - 2(.002) = 1.025<br /><br />Since the resulting thickness is below the discard thickness of 0.980, it would be best to replace the rotor.