1981-1984 Official Honda ATC250R Shop Manual, Page 202Get this manual
'82 ATC250R ADDENDUM
ATe 250R
METAL STOPPER PISTON SEAL
Remove the piston seal and metal stopper from the caliper cylinderClean the caliper grooves with brake fluidReplace the piston seal and metal stopper with new partsCAUTION
Do not use solvent for cleaningSolvent can cause deterioration of rubber parts
CALIPER CYLINDER INSPECTION
Check the caliper cylinder for scoring, scratches or other faultsMeasure the caliper cylinder 1.0