Yamaha GRIZZLY ULTRAMATIC YFM660FP Owner's Manual page 360

3. Refill with the same type of brake fluid. Mixing
fluids may result in a harmful chemical reac-
tion and lead to poor brake performance.
4. Be careful that water does not enter the mas-
ter cylinder reservoir when refilling. Water will
significantly lower the boiling point of the fluid
and may result in vapor lock.
5. Brake fluid may deteriorate painted surfaces
or plastic parts. Always clean up spilled fluid
immediately.
6. Have a Yamaha dealer check the cause if the
brake fluid level goes down.
8-95