I've got to replace the hose that runs to mine, the hose dry rotted and collapsed lol.

 

You youngun's won't remember vacuum wipers. My dad had a 1950 Plymouth I used to drive when I was a teenager. Going up hills, the wipers would slow down and almost stop working. When you were going downhill, they worked like crazy lol. Like Kyle said, the black ball is a reservoir. It helps provide vacuum for the times the engine isn't pulling much vacuum.

 

I finally got my 4x4 figured out after a month of research I noticed the t-case switch lines werent down as far as they could be, turns out when they replaced my t-case they put the vac lines on backwards even though there is an alignment nub on the line. I switched that around and bam 4 wheel drive baby!

But wat was weird to me the front axle seemed to be engaging even though the actuator wasnt moving.. is that possible?