Dodge Repair: Water outlet, 2.7 V6, water outlet, plenum

Question
The top from the water outlet popped off on a very hot day last week. The part is $112.00. If I had money I would have opted for the 3.5. Can I just reattach this with a strong adhesive?  And what is the little valve for in the top of the part?  

Answer
i would not attach it back  yeah the new one is 112  and it will require the upper plenum loose to get to the back bolts holding it down.. The screw on top is for the bleeding of the air once u get it installed. If u live near Atlanta I would do this for u.