1998-2004 Honda Foreman 450 factory service manual, Page 283Get this manual
BRAKE SYSTEM FRONT BRAKE WATERPROOF SEAL INSPECTION Check the waterproof seal for damage, fatigue or faulty installationMeasure the front brake waterproof seal lip lengthWATERPROOF SEAL
BRAKE DRUM
SERVICE LIMIT: 20 mm (0.79 in)
FRONT BRAKE WATERPROOF SEAL REPLACEMENT
Remove the waterproof seal from the brake drum by prying open the seal edgeRemove the whee hub
BRAKE DRUM
CALCULATE THE CLEARANCES BETWEEN THE DRUM AND SEAL Measure the drum and seal at a, b, and as shownCalculate the clearances and between the drum and sealA= -c B=b
Apply water to the entire new waterproof sealPlace the waterproof seal on clean surface plate, and press the brake drum into the waterproof seal, making sure that the clearances between the seal and drum ill reach the calculated clearance (see previous step)