1983-1985 Original Honda ATC 200X Shop Manual, Page 180Get this manual
BRAKE MECHANISM MASTER PISTON INSPECTION Check the master piston for score marks, scratches or other damageMeasure the master piston 0.0
SERVICE LIMIT: 12.645 mm (0.4979 in)
MASTER CYLINDER ASSEMBLY
Install the O-ring in the groove in the reservoirClean the mating faces of the master cylinder body and reservoir and coat the surfaces with small amount of adhesive (Three-bond No1211 or equivalent)Apply silicone grease to the piston cup and pour small amount of brake fluid into the cylinderPISTON CUP NOTE:
MASTER CYLINDER BODY
piston and spring as setDo not replace one without replacing