I'm going to change the engine oil and hydro oil and filters on my new to me 520H, I've followed the advice of you guys on this site for filters Napa Gold 1410 for the hydro and 1348 for the engine, but I'm not sure what I should be filling the hydro with as far as fluid?? does it take motor oil? or hydraulic oil?? and how much does it take? thanks for any advice!!