Among the many, many things I have to be thankful for this Thanksgiving Day is that the hydraulic system on my 300U is working again after my "rookie rebuild". Many thanks to those of you who offered thoughts along the way. I thought I would describe the "fix" in case it might save another guy some trouble one day.I bought my 300U on e-Bay about two years ago. Hydraulics (loader, Fast-Hitch and PS) worked OK at first -- slow but OK. Then about a year ago I worked the tractor hard all day for the first time moving some fill dirt. Right after that, the loader would not move every once in a while. This got more and more frequent until finally -- nothing. Couldn't get the bucket off the ground and had to remove it just to move the tractor. When the Fast-Hitch quit too I knew I needed to tear into it. At first I thought it was the hydraulic pump giving up because the pump had been making a loud, intermittant noise for a long time. But then I thought why would the thing have worked sometimes if the pump was gone? So I suspected that maybe it was just starving for oil -- perhaps due to "crud" in the system. But when I took the reservoir apart it looked pretty clean. Then when I got into the vaves it was looking REAL clean -- even in the finest screen. (Hey, how could I be thinking it would be dirty with all the oil that had been added to leak out of my loader cylinders???) So I just kept going thru it. No crud anywhere. I replaced all the "O"-rings I could find. The only thing I found in the whole system that looked really bad was the big "O"-ring at the top of the main oil pick-up pipe in the reservoir. That one was almost in pieces. So as I got ready to restart the thing I wondered whether anything would be different. Well, it was VERY different. All hydraulic systems now seem to be working well -- and much faster than before. So my conclusion is that the pump WAS starving for oil. But instead of crud, the thing was sucking air above the oil level in the reservoir. That intermittant "buzzing" of the pump was it getting oil just once in a while. Probably explains why it sounded differently going up or down a steep hill. So the very good news is the fix was an "O"-ring worth a few cents rather than a very expensive hydraulic pump. Hope this helps someone some day. Thanks again to all who offered suggestions during my somewhat inept repair effort. (Did I mention that a rainstorm managed to find its way thru three tarps and fill my open reservoir with water? Or that on the first restart my safety and flow control valve sort of, well, sprang a BIG leak when a snap ring let go? But then we know that tribulation builds character, right?) Hope you all had many things to be thankful for today as well. Bob Kirk
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