Car was garaged for 20 years, started the engine, power steering makes this humming noise when operating, It seems it is sucking in air from somewhere, the fluid canister is bubling oil (fine buble, some thing like foam), An y advice?

Try the following and see what she does. Bubbling fluid may mean air in the system so with the engine running and fluid properly warmed turn the steering lock to lock several times. Don't hold it against the stops then check the fluid level and adjust if necessary.

Thanks, The noise has deacreased dramaticaly. I however still have oil seaping out from the buterfly nut. Does this nut need to be sealed with a washer or it lets air balance pressure inside the container