What's the little black plastic tube on the TH400?

I'm switching from the TH350 to a TH400 trans. for my new build. While moving the transmission yesterday I broke the little black plastic tube off.

What is it for?
Can I use a fitting and insert into what is left of the tube to make the vacuum connection?

Here's a picture of the broken tubing....man was it fragile :rant:

 

Breather tube.

 

Yep - it's a vent.

K

 

O.K. so I don't need to worry about it, even though it is broken and very short?

 

I would'nt worry about it.

 

Thanks guys.