Who Can Tell Me What This Is?

While dropping in the new motor today I broke the tip off of this.
Can anyone tell me what it is and if so do you have the part #?
It's located on the drivers side inside fenderwell mounted along with the vacuum ports.
The tip I broke off has a vacuum line that goes to those vacuum ports.
TIA

http://rides.webshots.com/photo/2402913760101036593AvVpce?vhost=rides

http://rides.webshots.com/photo/2879397720101036593jtVRMj?vhost=rides

Thats the Vacuum pump...

Nope, not the pump. The pumps on our OBS trucks are belt driven. Must be some kind of vac sensor? I dunno.

I'm going to take it off and see if it has a part # on it.
I assume it has a purpose or else they would not have put it on there.

I think that is the sender to turn on the brake lite if the vac pump fails or there is a vacuum leak.

Tom