questions about a #44 hydraulic unit mounted on a D4-6U

Hello all!
First, I'd like to thank Mr.22 for making this all possible! Second I have some questions now that I finally have assembled, dis-assembled, then re-assembled the blade, trunnions, and parts of the pump/coupling and now it's functioning. Question 1: is the cap on the hydraulic fluid reservoir supposed to be vented? (mine is not). Question 2: is there a "proper" method for putting fluid in the reservoir? (I just put enough in to lift the blade, then lifted it all the way, then filled it to what I deemed a "suitable" level (about 3 gal.)). As always THANKS for any help and advice,

Orchard22

The hyd unit is not vented and the oil level should be visable in the filler neck screen with blade lowered to the ground. Do NOT over fill.