Honda TRX680FA Service Manual page 430

BRAKE SYSTEM
Remove the master piston, primary cup and spring.
Clean the master cylinder, spring and master piston
in clean brake fluid.
SPRING
MASTER PISTON
PRIMARY CUP
INSPECTION
Check the piston cups and boot for wear, deteriora-
tion or damage.
Check the spring for damage.
SPRING
MASTER PISTON
PRIMARY CUP
Check the master cylinder and piston for scoring,
scratches or damage.
Measure the master cylinder I.D.
SERVICE LIMIT: 14.055 mm (0.5533 in)
Measure the master piston O.D.
SERVICE LIMIT: 13.945 mm (0.5490 in)
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