Yamaha XZ550RJ 1982 Owner's Manual page 175

1. Lower level
I. Niveau minimum 1. Nivel inferior
3. Be careful that water does not enter the
master cylinder when refilling. Water
will significantly lower the boiling point
and may result in vapor lock.
4. Brake fluid may erode painted surfaces
or plastic parts. Always clean up spilled
fluid immediately.
5. Have a Yamaha dealer check the cause
if the brake fluid level goes down.
Brake fluid replacement
-163-
1. Complete fluid replacement should be
done only by trained Yamaha service
personnel.
2. Complete fluid replacement should be
done whenever the caliper cylinder or
master cylinder is disassembled, or the
fluid becomes seriously contaminated.