Ford 3000 question.

[aerospares]

I'm new to the forum, and new to my Ford 3000. I've been reading some of the posts, there sure is a mountain of knowledge in these pages. If anyone out there has knowledge of this model I have a few questions. The three point was working with a 'jerky' motion when I bought it last month. I drained the hydraulic oil, 5 gals came out, very dirty, and quite thick. Not like the trans/hydraulic oil I expected to find. I replaced it with Universal Tractor Fluid from Parts Plus that I had in the barn. I haven't tried it with much weight on it, but the lift seems to be working okay now. I only had five gallons on hand and will get more tomorrow, what is the total amount needed to fill to the proper level? Also, how hard is it to change the hydraulic oil filters? I'm sure I'll have many more questions as I get to know her, but this will get me started in the right direction.
Thanks,
gr