Do I recently purchased a Shimano slx and I like to have no breaks on and just thumb the spool so I can cast farther. But whenever I cast with some force breaks randomly click on. I don’t know if this is just the mechanism just so the spool can slow down or if my pins are just broken. I am really confused and frustrated because the thing is brand new please help..

Turn your brakes on a loosen the spool tension. 

1 hour ago, Thatneshortkid said:

Do I recently purchased a Shimano slx and I like to have no breaks on and just thumb the spool so I can cast farther. But whenever I cast with some force breaks randomly click on. I don’t know if this is just the mechanism just so the spool can slow down or if my pins are just broken. I am really confused and frustrated because the thing is brand new please help..

did you lock the brake blocks on the spool?  There should be four plastic blocks under the side plate. Lock them next to the spool to turn them off. Be advised, if you turn them all off you have zero braking regardless of the outside dial. 

Shimano SLX with MGL spool I use 2 on-2 offfor maximum casting distance using .011 diameter mono or FC line. I started with 4 off and changed to 2 off casting into the wind and don’t see any difference in casting performance.

Tom

The brakes click on and click off.  Push them so they do not move. When they don't move they are off and you have free spool.