I'm a idiot sometimes (well, a lot of the time- but don't tell anyone).
Got a new to us 40 ton grove a while back, and we have some of the issues sorted, so yesterday I pulled it outside and put it up on jacks, I haven't had time to even set the thing up to see how it runs/operates. So I ask one of the other guys, (they set it up earlier) where the swing brake is. He points to the pedal on the floor, it isn't a swing brake, its a 360 house lock. I tell him that isn't it, it should have a electric switch brake also.
Set the crane all up, and the boom is good, winch, outrigger controls are still messed up upstairs, but the worst thing is the swing. Rough, won't start and stop easy, swings worse than the mack/ national we have. I get out and mumble grumble kick around about it. Piece of junk crane etc. etc. The other guys are like "don't give up on it, its just probably something wrong".
Well the problem is operator error, I found the electric swing lock switch this morning, and with the swing brake switched off, the crane swings like a grove should, smooth and easy to control. I'm just dumb sometimes.