I inherited a John Deere 2040 (80s model) and let someone use it. Love it and loved working it as a kid but now it is mine to maintain which Dad always did
So, after loaning it out ....the hydraulics will no longer work for the aftermarket installed front-end loader and the three point hitch. The differential lock petal below the seat on the left side appears to be much looser than normal but this should not affect the hydraulics. Any ideas on the hydraulics. I can not even move the tractor because there is NO HYDRAULIC and the loader will not lift up at all. But the fluid on the stick says full 
Thanks for any help and have a great day...I looked for a manual online put I could not find one so I am asking. Thx ps: Does anyone have a pdf of the owners manual or know where I could purchase on on-line? Also how to I unlock the differential lock...