1985-1986 Honda ATC250R Shop Manual, Page 213Get this manual
HYDRAULIC DISC BRAKES
FRONT MASTER CYLINDER
REMOVAL
Drain brake fluid from the front hydraulic systemRemove the front brake lever and disconnect the front brake hose from the master cylinderCAUTION
void spilling fluid on painted, plastic, or rubber partsPlace rag over these parts whenever the system is serviced When removing the oil bolt, cover the end of the hose to prevent contaminationRemove the throttle housing, then remove the master cylinder from the handlebar
DISASSEMBLY
Remove the piston boot and the snap ring from the master cyl inder bodyRemove the master piston and spring from the master cylinderClean the master cylinder, reservoir and master piston in clean brake flu id