2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 346Get this manual
BRAKES 3Mount dial indicator as shown to measure disc runoutSlowly rotate the disc and read total runout on the dial indicatorReplace the disc if runout exceeds specifications
RemovalReplacement
NOTE: To reduce the possibility of warping, try removing the brake disc mounting bolts before applying heat to the bolts1Apply heat to the hub in the area of the brake disc mounting bolts to soften the bolt locking agent
= In mmBrake Disc Runout Service Limit: .010".254 mm 2Remove bolts and disc3Clean mating surface of disc and hub4Install disc on hub5Install new bolts and tighten to specification