2004-2005 Honda TRX450R Factory Sevice Manual, Page 284Get this manual
HYDRAULIC BRAKE Remove the snap ring using the special tool
TOOL: Snap ring pliers
07914-SA50001
SNAP RING PLIERS
Remove the master piston and springClean the master cylinder, reservoir and master piston clean brake fluid
INSPECTION
Check the master cylinder and master piston for scoring, scratches or damageCheck the piston cups for wear, deterioration or