W124, MPG Products to Increase Mileage

In changing the serpentine belt I pulled at a line and broke the non-return valve in the middle of the main brake booster vacuum line. My car won't stop now and it's slightly important to do so because I have to get this car inspected for a state safety inspection. I'm thinking they won't look too kindly on a car that doesn't stop ;)

From the schematics, this is the brown plastic line that gets the vacuum when the key is shut off -- so everything adds up. I'm trying to find a quick fix as I wait on parts.

#1: I haven't been able to find just the valve, I think the line has to be replaced entirely?

#2: Is this as simple as unscrewing and reconnecting from the pump to the booster? Since there isn't fluid/anything else to deal with I wanted to make sure I don't neglect anything.

Hello everyone,
just wondered what proper compression is for a diesel. I have a 92 300D, and my shop recently did a cold compression test with the following numbers- #1-340, #2-330, #3-290, #4-320, #5-320.
He said that these were pretty good for a car w/ 270k- I just wondered what anyone else thought. The car seems to start fine, and runs well.
Thanks!