[cwl1979]

I personally wouldn't refill a system with ATF. I would look for a quality hydraulic oil such as Chevron 5606A. Its very similar to ATF in fluidness and its also red in color, but it doesn't have a bunch of the additives that ATF does. When in a pinch ATF would be fine, however ATF has a tendency to deteriorate rubber lines pretty fast causing more issues down the line.

Just my thoughts on it, from my experiences.