2004-2005 Honda TRX450R Factory Sevice Manual, Page 285Get this manual
HYDRAULIC BRAKE Coat the master pis ton and piston cups with clean
DOT brake fluidInstall the spring onto the piston endDo not allow the pis ton cup lips to
MASTER CYLINDER
Inst all the spring and master piston into he master cylinderPISTO CUPS
turn Inside outBe certain the snap
ring is firmv seated
MASTER PISTON
Inst all the snap ring into the groove in the aster cylinder using he special tool
in the groove
Snap ring pliers