1983-1985 Original Honda ATC 200X Shop Manual, Page 189Get this manual
BRAKE MECHANISM SNAP RING
Remove the rubber coverRemove the snap ring and push rod from the master cylinder bodyRemove the master piston, primary cup and springIt may be necessary to apply small amount of air pressure to the fluid outlet to remove the master piston and primary cupClean all parts with brake fluid
SNAP RING PLIERS
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CYLINDER 1.0INSPECTION
Measure the inside diameter of the master cylinder boreSERVICE LIMIT: 14.055 mm (0.5533 in) Check for scores, scratches or nicks
PISTON 0.0INSPECTION
Measure the master piston 0.0SERVICE LIMIT: 13.945 mm (0.5490 in) Check the primary cup and piston cup for damage