got a question, yesterday at sunrise it was pretty cold out maybe 30, i didnt look, but went to work did my safety checks and fired up our cat 325B excavator, warmed it up for probably 30 minutes,and climbed up on the high bank i was working on, everything worked as it should until, i went to dump the bucket, while it rotated to the closed position when it filled, like it should, when i went to open the bucket it would not rotate past about halfway, not enough to dump even with the dipper, and boom all the way up, i finally got it to dump by wiggling the control stalk just slightly, moving the control all the way to the right caused loss of control of the bucket, and it rotated almost closed by itself, hydraulic fluid is full, with about 30 hours on a full change and filters, any ideas? after about 2 hours it returned to normal operation by itself, that's kind of annoying to say the least and i don't really need the issue all winter