1999-2004 Honda TRX400EX FourTrax Service Manual, Page 204Get this manual
HYDRAULIC DISC BRAKE
BRAKE DISC INSPECTION
Visually inspect the disc for damage or cracksMeasure the brake disc thickness at several points
SERVICE LIMIT Front: 2.5 mm (0.10 in1 Rear: 3.5 mm (0.14 in)
Replace the brake disc if the smallest measurement IS less than service limit
Check the brake disc for warpage
SERVICE LIMIT 0.30 mm 10.012 in)
Check the bearing for excessive play, if the warpage exceeds the service limitReplace the brake disc if the bearings are normal
FRONT MASTER CYLINDER
CAUTION:
MASTER CYLINDER