If its the samething then you can use psf you have in your trany & t-case. I've always refilled a dry powersteering system with psf but topped up the pump with atf if no psf was around. Some once told me atf is higher detergent than psf but otherwise the its samething. Refilling a complete system with atf that was on psf can was the sludge out of it and start leaks.