1988-1994 Honda TRX300 Fourtrax, 1988, 1990-1994 TRX300FW Fourtrax Service Manual, Page 212Get this manual
BRAKES INSPECTION Measure the master cylinder 1.0SERVICE LIMIT: (TRX300) 12.755 mm (0.5022 in) (TRX300FW) 14.055 mm (0.5533 in)
Measure the master cylinder piston 0.0SERVICE LIMIT: (TRX300) 12.645 mm (0.4978 in) (TRX300FW) 13.945 mm (0.5490 in)
ASSEMBLY
CAUTION
(3) PISTON
Keep the piston, cups, spring, snap ring and boot as set; do not substitute individual partsCoat all parts with clean brake fluid before assembly Dip the secondary cup in brake fluidInstall the primary cup and spring to the pistonInstall the oil seal, piston assembly, snap ring and bootCAUTION