Question about PS cap vent?

I bought a new PS cap a while back(lost my old one on the trail somewhere). but the new cap has a nipple and hole on the top, i just changed my PS pump because it was going bad, frothing and turning brown, and seal was leaking.
either way, im about to go wheeling tomorrow, and i need to know

Should there be a hole for a vent on top of the cap, and if so a hose?

Thanks guys

No hose. The original caps were prone to leaking and the improved version was like the one you just got.