I made my own pipe and tube bender and powered it with an air over hydraulic pump. It's made for a hoist or jack, so I leave a hundred pounds of air on the return side of the cylinder and when I step on the "let it down pedal" it works like a load or spring to return the cylinder and push the oil back to the reservoir.
Today I noticed the cylinder squeal a little so in the absence of proper hydraulic oil I used a few drips of snap on air tool oil in the air side. Bad idea, the rubber o ring in there grabbed the inside of the tube and refused to let go. Then I tried 10W belray fork oil, seemed legit. Stuck it hard.
I had to take it apart, clean it and lube the piston seal with some of the hydraulic oil from the pump and wet side of the cylinder, I spilled it everywhere and used a little 20W50 on a rag to wipe the bore of the cylinder with.
My lead hammer got a workout getting it apart without dinging anything but now the piston slides back and forth again.
Moral of the story, if you don't have the right fluids, go get them.