BMW F 800 GS Rider's Manual page 94

Check the brake-fluid
8
level, rear brakes
A low fluid level in the
90
brake reservoir can allow air
to penetrate the brake system.
This significantly reduces braking
efficiency.
Check the brake-fluid level at
regular intervals.
Make sure the ground is level
and firm and hold the motor-
cycle upright.
z with centre stand
Make sure the ground is level
and firm and place the motor-
cycle on its centre stand.
Check the brake fluid level in
rear reservoir 1.
Wear of the brake pads
causes the brake fluid level
OE
in the reservoir to sink.
Brake fluid level, rear
(visual inspection)
DOT4 brake fluid
It is impermissible for the
brake fluid level to drop be-
low the MIN mark.
If the brake fluid level drops be-
low the permitted level:
Have the defect rectified as
quickly as possible by a spe-
cialist workshop, preferably
an authorised BMW Motorrad
dealer.