Carsen: I have owned a 300U with loader since about 1975. My pump is original with about 5000 hours and it works fine. This tractor has been used with fast-hitch equipment many years in the fields of my farm and now the loaders is used year around. One problem I had was plugging of the screen in the reservoir under the seat. When the screen was plugged oil flow was greatly limited. It's heavy for an old man to remove the reservoir so the second time it happened I removed the internal screen and added a large capacity industrial type hydraulic oil filter in the return line to the pump on the right side near the engine block. That solved the problem and the screw-off filter is easy to change. The filter kit was available through NAPA. Good Luck, Ken