CX700 Case Swing Problems

I'am working on a 700 Case Excavator , when I swing to the right & return the joystick to the neutral position it doesn't stop , but continues to creep to the left very slowly . As soon as the engine returns to idle approximately 5 seconds the brake does apply . Everything is fine when I swing left , when the joystick returns to neutral in there is no movement . Any suggestions would be appreciated, thanks .

CX700 Case Swing Problems