What's Inside the Front Diff Breather Hose "Valve"?

For want of something to do, I carefully removed the little valve from the top of the front differential breather. When I held it vertical so the cap was up and then blew and sucked on the other end, it seemed like there was some kind of ball inside, perhaps with a spring. I could blow through it freely but when I sucked on it, something stopped the air from flowing back through (or most of it anyway).

So thinking that I could clean the inside of the valve, like a fool I carefully removed the cap. Lo and behold, there was nothing inside the cap. No ball, no spring. I didn't drop anything that I know of.

Does anybody know what should be under the cover of this gizmo??? If anything?

 

Just a one way/check valve.

Replace it since you took it apart; it's cheap.

May as well run a line from it to extend the breather to a higher location to prevent from being submerged in water.

 

That's what I thought. Just like the 1-way from the rear differential.

After I removed the valve from the truck I blew on it and it sorta worked. Then I decided to pop the cap. Halfway through removing it the valve stopped working and I could blow both ways through it. After removing the cap I looked all around the workbench and the floor hoping to find something like a spring and ball but alas, couldn't see anything.

I'll buy another one when I get to the dealer.

 

the front is actually already extended, it sits above the opening of the wheel well.

now the back, I still need to do that. maybe next gear fluid change which is overdue but too cold out