1976 [?] ford 1600, 2wd 2cyl diesel - bradco backhoe 7ld questions

[Jake.P1028]

thank you for having me, this is my first post here - I recently purchased a running driving ford 1600, attached was a 770Loader [?] and a Bradco 7ld Backhoe - Upon investigation i noticed the backhoe has its own hydraulic fluid reservoir, and upon inspecting fluid noticed it to be milky- i know this is a sign of water\moister in the fluid - and understand a drain, flush, refill is in order. my Question is whats the best fluid, and whats the capacity? I can post pictures if nec, the res. does not have a Dipstick, but does have 2 plugs on the side of the tank, one lower than the other but neither are on the bottom bottom, so a fluid sucker to pull it out, but then comes the refilling - with no dipstick would i just top the res all the way to the breather? - TIA .