I have a 20ton bottle jack that is low on fluid. I found the fill plug on the side of the cylinder and put in some fluid. I did not have much fluid on hand, so I put in what I had. It now jacks up halfway, so I know it works, but needs more fluid. The question is how full should I make it? Do I fill it until it runs out the fill plug, or another level?
Also, I was wondering if I can use general purpose hydraulic tractor fluid rather than the more costly small bottles labelled as "hydraulic jack fluid"?
I found several websites abotu this. None said how much fluid to add. More than one said DO NOT use brake fluid. All seemed to recommend the actual "hydraulic jack fluid", one said transmission fluid works, but is not recommended. Yet none suggested hydraulic tractor fluid (which operates all hydraulic cylinders that are connected to the tractor, and thus is used in the same way). It's a lot cheaper per ounce to buy a gallon of tractor fluid instead of a quart or pint of jack fluid.
Thanks