2002 Yamaha YFM660 Grizzly factory service and repair manual, Page 305Get this manual
FRONT AND REAR BRAKES
3.Check: Brake fluid level Refer to "CHECKING THE BRAKE FLUID LEVEL INSPECTION" in CHAPTER 34.Check: Brake lever or brake pedal operation Soft or spongy feeling Bleed the rear brake systemRefer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM" in CHAPTER 3