Thanks to a lot of helpful advice 8 months ago I finished rebuilding my '49 Hydrovac, and finally installed it last week along with new master cylinder. However I didn’t put the oil in its tank yet, where would you pour it in? And how much? I know it’s not much, maybe a cup or less. I read of one guy using mineral oil, does that sound right?
Thanks much


1949 Chevy 6400 two ton, 2 speed rear end, 235 engine, 13 foot hydraulic dump bed.