Focus,
The VERY easiest drill would be to go to your FLAPS and pick up a quart of "jack oil"! It will be a generic hydraulic oil and will undoubtedly be compatible with the oil in your HF crane.
If you want to be technical, any AW-32 hydraulic oil would do....even ATF would work! Because there isn't a powered pump involved, the system is very forgiving.
I hope the hoist didn't have a brand new engine hanging from the hook when it blew its brains!
Stuart
