The band brake wraps around the clutch drum of the Good Luck chainsaw and engages when the brake lever is pushed or on kickback. It is an operator safety feature.
The band needs to be replaced if it is worn through, torn, or does not hold the drum: the chain keeps rotating with the brake engaged. It is worth checking the brake before every job.
After replacement, check the unit at idle and under load: there should be no leaks, play or unusual noises.
