5020 hydraulic issue...please help
We bought a place that came with a JD 401 and an Allis Chalmers 5020. I checked the fluids on the 5020 and it started right up. It has a 5' shredder on it and I started cutting around the house and barns. It was cutting great and I started to loose hydraulics on it after about an hour. I shut it down, checked the fluid level as it has a small drip leak on one of the fittings. I added just a little fluid and started it up the next day. Same story, the hydraulics worked fine for the first few minutes but then stopped working. I wouldn't lift the shredder. I opened up the fill cap and the fluid was a little bit 'milky' so it definately has a small amount of water in it. I'm wondering though if it may have a weak pump since it works when the machine is cold but as soon as it warms up it stops working.
Any advice anyone can offer will be greatly appreciated.