1999-2002 TRX400EX Fourtrax Service Manual, Page 204Get this manual
HYDRAULIC DISC BRAKE
BRAKE DISC INSPECTION
Visually inspectthe disc for damage or cracksMeasurethe brake disc thickness at several pointsSERVICE LIMIT Front: 2.5 mm (0.10inl Rear:3.5 mm (0.14 in) Replace the brake disc ifthe smallest measurement IS less than service limit
Check the brake disc for warpageSERVICE LIMIT 0.30 mm 10.D12 in),
Check the bearing for excessive play, if the warpage exceeds the service Ii mitReplacethe brake disc if the bearings are normal
FRONT MASTER CYLINDER
CAUTION: void spilling fluid on painted, plastic or rubber parkPlace rag over these parts whenever the system is servicedWhen removing the oil bolt, cover the end of the hose to prevent contamination