Sorry guys, brakes again

[RedRustBox]

Hey, this is puzzling me,

Look at this,
http://i205.photobucket.com/albums/bb212/Luke228_photos/100_0699.jpg

The vacuum line connects to it and another line comes out, which was not plugged on to anything, then i found where it is supposed to connect to which looks like a proportioning valve or something (not a brake expert as you can tell) any ideas appreciated

Thanks

[Mudball]

Looks like a pressure canister to me.. it's purpose is to hold negative pressure, so when you hit the brakes, the brake booster will have the vacuum it needs - no matter what rpm you're in.