I posted about this but am making a new post. I oreviously thought there might be a leak in the power steering hose that connects to the reservoir or the reservoir itself, but I took everything apart and didn’t see any cracks. After some more testing it looks like the leak is coming from the top of the reservoir, like out the cap itself? What could the problem be? I saw online that there may be a missing O ring where the hose from the reservoir and pump connect. I’ll attach some pictures. Thanks for any help. 

The reservoir cap isn't sealed but it's strange to have it leak.  With engine on, steer left/right a couple times quickly, if the oring was leaking it would suck in air and cause a whining noise and random choppiness in the steering wheel.  You could have someone steer back and forth while you check in the reservoir with cap off and see if there are any bubbles.

I don't recall ever having fluid leaking out the top of the reservoir cap, but guessing if there's an air leak at the top where the steering pump is, any fluid higher than the reservoir will eventually drain back down into it.

Betting either that upper host end is so hardened and brittle, the rubber can't contract any more even with the hose clamp.  The oring is under that black elbow, I usually replace it with whatever fits from the auto store.

I've read on an OB forum where that belt guard connecting the PS inlet to alt bracket moves as engine is loaded causing the PS inlet o-rings to move enough to suck air. Like nvu said, replace those o-rings to start with, replace both PS reservoir hoses. Put the PS inlet bolt into the belt guard first, then tighten the alt pivot bolt, making sure the alt washer is in the right place there. If that guard is at an angle then that washer is not in right place.

Some people delete the belt guard. YMMV.