2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 271Get this manual
FRONT AND REAR BRAKES
3Air bleed: brake system Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM" in chapter 34Check: brake fluid level Brake fluid level is below the "LOWER" level line Add the recommended brake fluid to the proper levelRefer to "CHECKING THE BRAKE FLUID LEVEL" in chapter 3
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