Kubota M6800 hydraulic whistle?

[sixdogs]

I have a new-to-me Kubota M6800 with 400 hours that I bought at an estate sale. In starting to use it, I noticed a very faint "whistle" that almost sounds like a fan belt that is slipping a tiny bit. I changed the belt. It has a loader but it's not on at the moment.

The tractor needs to warm up and then I hear this slight whistle. If I push the joystick lever one way and hold it, the whistle seems to go away. A couple times I made the whistle go away by using the hydraulic remotes (that were hooked to a cylinder). I worked the hydraulic levers and joystick just to make sure nothing was sticking.

Also, I put my mechanic's stethoscope on the pump and I can hear the whistle in there. Any idea what's going on or what to do next? I have no idea.

 

[sixdogs]

Here's what the problem was. The draft control adjustment rod had come loose and lengthened itself a little bit longer and that, it turn caused the very slight hydraulic whistle.

 

[Tx Jim]

I'm glad you located the cause of the whistle sound. Noise you heard was probably 3 pt relief valve being pushed off it's seat.