6400 hydraulic pump runs hot

[tim7]

I have a JD 6400, all my hydraulic functions seem to work fine, but I am hearing kind of a low pitch bussing sound from the hydraulic pump when no load is put on the pump, however when I turn the steering wheel or open the grapple fork this bussing sound seems to turn into more of a chatter sound. When operating the other loader fuctions the sound does not seem to change much.
Any help would be much appreciated.

 

[JC-jetro]

I have a JD 6400, all my hydraulic functions work fine, but I am hearing kind of a high pitch bussing sound from the hydraulic pump, and it is running hot.
Any help would be much appreciated.

What is inlet and Outlet pipe temperature immediately in and out of the pump. Can use a non contact infra red thermometer. There is a lot of variable to consider such as the ambient temp, size of the diffy/transmission oil reservoir, how long the tractor was running just before the test. A nearly dead headed pump transfer all the extra flow to heat and it warms up really quick. lack of proper inlet flow can cause the pump to work extra hot. Does manipulation of 3 point or loader if you have changes the noise coming out of the pump?

JC,