2656 hydraulic noise

Anyway, when I was running yesterday, there is a buzzz buzzz sound coming from the hydraulics and louder around the pump area. It is kind of a steady pulsating buzz with each buzz lasting about a half to one second. Is this cavitation or what? And what would cause that.

I have decided to pull the flow divider off to check it to see why the steering is so hard on it. I talked to a hydraulics repair business and they would bench test it for $110 but he said they rarely go bad. He thought it was a pump not putting out enough or the steering cylinder seal leaking internally.

I can operate the backhoe hydraulics and yesterday I moved around a 1500# hay bale with the front end loader. However, the hydraulics did make a lot of loud whining noise when it picked it up with a little hesitation but it does come up and it held while I moved the bale around which took a while in the mud.

It has probably always done it, but I'm not sure this steady pulsating buzz buzz noise was as loud before. I probably ran it about 2 hours yesterday after I got the carb back on it which I'm going to take back off this afternoon again since the new needle and seat doesn't shut off the gas when it is not running (the gas just runs out the carb intake).

The hydraulics weren't quite as noisy today. The buzz is more of high pitch whine/buzz. When you hold either of the pump outlet hoses, I can feel the pulsation that is consistant with the noise. It doesn't feel like a steady flow. The pump outlet hoses however don't vibrate back and forth like the hose going from the loader valves back to the backhoe hydraulic setup. That hose kind of jumps around a little.

I am already a few gallons over full but I can add some more to see if that will work.

My next step will be to figure out what cavitation is and sounds like. But if either or both pumps were bad, then I probably shouldn't be able to pickup a 1500 # bale. Then I will start pulling lines loose to see if they blow out high psi fluid. I pulled a steering cylinder line off the other day and the best it would do is puke a little fluid out.