Ok... I took the valve out. Its a suction pump. part #058 133 753 b.

Why would the end pop off of it like this? Is this a sign of some
other problem in the vacuum system?
The valve (or pump, as its called) didnt fail or clog, that I can
find. It just seperated into two pieces. Being held together by the
tension of the hoses that it uses to function.

here is the whole pump....
http://jake.rakestraw.com/images/whole.jpg

and here it is with the valve assembly snapped apart
http://jake.rakestraw.com/images/broke.jpg

Is the popping apart of the pump a safety measure to keep something
else more vital from exploding?

Jake