It really depends on how the recycled fluids will be used. Our local recycler says he's happy with a mixture of engine oil, gear oil and hydraulic fluid because he sells the stuff to a company that filters it for solids, then sells it as boiler fuel for large ocean going tankers. The tankers will apparently take anything that burns as long as it does not have enough solids to gum up their tanks, etc.
BTW I was emptying 11 gals of hydraulic fluid (1 change of tractor hydraulics) into the used oil hopper as he explained the details. I did ask first
I save the anti-freeze (poured back into the original containers*) until we have a local "hazardous waste recycling" day. Then I just recycle it with other household hazardous waste (e.g. paint, pesticides, etc.).
Funf Dreisig
*The rule at our "hazardous waste recycling" is that the label on the outside of the container must match what is on the inside. The don't even let you get out of your vehicle. They take it out of your trunk and sort it on the spot based on the label.