I recently bought a john deere 5210 tractor with 520 loader and noticed the lift cylinder is leaking oil, but it worked fine for a few days. Now when I start the tractor something is making noise, I think its the hydraulic pump but not sure (also the noise seems to go away after running a little while). But the problem is the hydraulics dont work, when I try to lift the loader it will try to lift and will sort of bump up, not smoothly and the power steering is not working well anymore. Yes the hydraulic oil is full but the oil looks like it has some water in it, its kind of milky but the fluid thats been leaking from the loader is like coffee. I Know the fluid should be changed but I dont understand why it was working fine when the seller was demoing and while I had it for a few days and suddenly stop working. Any ideas? thank you