About the floor jack it has a fill screw and next to that is a adjusting screw how many turns in or how many turns out must i go.When i try to jack up my car it will not lift it.
Not to nit pick, but actually the fill plug screw can be seen on the left side of the bottle about half way up the side.
I think he is talking about a rather large looking plug on most floor jacks sold today that is located back on the square base of the block and sometimes is flush with the block, and other times protrudes above the surface of the block. In either case it is located in close proximity to the handle and the plunger rod that actually actuates the lifting arm up and down. The described screw and location is not any adjustment though, once the plug/screw is removed from the square base of the bottle all you would find is perhaps a spring and a couple of ball bearings or the like.
No, if that jack isn't lifting I still say it must be leaking and low on fluid, no adjustments are needed. Also fluid does not evaporate from jacks, it leaks, thus my saying it is leaking. They do not simply get low on fluid.
If it's a floor jack it should have a fill plug on the top back of the jack. The screw should be a bleed screw. You open it and pump the handle to get all the air out of the system.