I just purchased a 2000 Takeuchi TB070 4500 hrs on Saturday. For a demonstration, the guy worked it for about a half hr digging a trench. He worked it hard and everything sounded smooth as silk the whole time. I bought it. When they were loading it up on the trailer on Monday, I noticed the hydraulic pump was whining when traveling, using the boom or bucket but not swing and not blade. I told the guy that I didn't hear that noise on Saturday. He said well it can only be a few things, low on hydraulic oil, plugged filters. When they dropped it off, I took out the hydraulic filter and the strainer. Both of those looked fine. I did notice there were bubbles in the oil. The oil level was over full. I completely drained the hydraulic tank to check for foreign material. Nothing. The hydraulic oil filter has a plastic valve assembly that sits right on top of the filter(item 8 in the photo) . This valve looks to be adjustable and it looks like somebody has cranked it down as tight as it will go. In the photo you will see that I backed the locking nut off. Is there an adjustment on this valve? I took the piping off of the bottom of the hydraulic pump from the hydraulic tank and inspected the Orings and hoses..all good. I have not put it back together yet. I have ordered an annual filter kit for this machine that should be here around the 8th of August.
Good day Kanui You noticed bubbles in the fluid this could be responsible for the whining suggest that you full stroke the cylinders a few times and check that the tank has become pressurised bu pressing down item 3 in your illustration.Please see the attached for explanation. Kind regards Uffex
That little plastic valve is the filter bypass, if the filter element gets packed up enough that valve will open before the filter media can rupture. Dunno about the setting of it.