2008 Yamaha Raptor 250SE / 250SE2 Factory Service Manual, Page 228Get this manual
FRONT AND REAR BRAKES EBS00413
CHECKING THE MASTER CYLINDERS 1Check: brake master cylinder WearscratchesReplace the brake master cylinder assembly brake master cylinder body CracksdamageReplace brake fluid delivery passage (brake master cylinder body) BlockageBlow out with compressed airFront Rear