Noise coming from under seat, hydraulic noise

My 1023e has a rattling sound coming from the hydraulics under the seat at idle. if i increase the throttle is goes away. if at idle i manipulate any of the hydraulics like turn the steering wheel it quits until i get finished turniing the wheel. this only happens at idle.everything works fine but just curious what this noise it only started recently. my tractor has 60 hours on it.
thanks