BMW K 1100 LT/RS - Manual (Page 291)

34.33
Brakes rubbing.
no
Check hydraulic system.
Is there a defect in hydraulic system operation? yes
Rectify defect.
no
Check brake piston.
Are brake pistons jammed? yes
Change break piston/master brake cylinder.
no
Check brake discs/wheels.
Is lateral runout too large? yes
Replace brake discs/wheels.