E120B swing noise

I was using my E120B to remove trees and I took lunch break and came back out. Worked it for about a minute or so and started to get a noise from the swing motor, when I would start to swing and then release the lever it would slow down very little then after 3 seconds the swing brake would engage and stop the unit. It almost sounds like a grinding noise when I start to swing the hoe, more noise the harder I accelerated the swing. Once it gets up to full swing speed, it is quite. I am thinking there is something messed up with the dynamic swing braking….but could this make it have a noise when it starts to swing? Could the 2 valve on side of swing motor be stuck open or shut….. any ideas would be great, thanks.