On top of the 4L60E there is a vent line(im guessing) and a small vac check valve. does it really need the check valve or can i just put a piece of vac hose on it and go.. Also what would the check valve be for???

 

The check valve is to keep water etc from traveling back up the tube. If you dont live in and area where you will be in any deep water or puddle or high mosture areas its probably fine without it. Well unless the car sets a long time then i have noted that dirt dobbers like to make nest in them .

 

Cool good to know..