1999-2004 Honda TRX400EX FourTrax Service Manual, Page 208Get this manual
HYDRAULIC DISC BRAKE
INSPECTION
Check the caliper cylinder and piston scoring, scratches or damageMeasure the caliper cylinder I.D
SERVICE LIMIT: 34.02 mm (1.340 in)
Measure the caliper piston O.D
SERVICE LIMIT 33.87 mm (1.333 in1
ASSEMBLY
BLEED VALVE CALIPER BODY PISTON SEAL
PAD PIN PLUGS