BMW F 650 GS Manual page 72

Fuel and lubricants
Brake fluid
3
70
Coolant
Capacity
F 650 GS
DOT 4
We recommend BMW brake fluids
Use only new brake fluid to DOT 4
specification.
Brand-name long-life antifreeze
and corrosion inhibitor
Use only nitrite-free antifreeze and
corrosion inhibitor.
1.37 US quarts (1.3 l)
(0.1 US quart/
0.1 l in expansion tank)