Sorry, not done yet, what a let down. But has anyone else used DOT air brake/line fittings for vacuum lines before? here's what I'm talking about, the black plastic connectors.
vac lines Fastenal

They use hard line and are a push connect type. You just cut your line, push it in and pull and its all set. To remove you push them back in and hold the connector to remove. They are good to over 100psi, and pretty small and clean.

1/2"Tube x 1/2"Tube P-T-C Composite DOT Union Y | Fastenal

Anybody done that? I have them availiable to me at work, so with the whole 6 or 7 lines I need, I could make it look pretty damn good and build brackets to hold it all that would keep everything straight and linear. Much better than the rubber line mess.

 

Yep, used them plenty of times. They are awesome. I've built water/meth injection setups, vac systems etc. with them. I'm far too cheap to put them on my car, but I wish I could.

 

I will see how many I can nab from work without getting bitched at. 830,000 in inventory, I'm sure 10 bucks of dot fittings won't be anything to cry over. I'm thinkg 90's, straights, and y's with a few 1/4 or 3/16in pipe thread fittings.

 

They work great for pressure lines, not sure if they'll seal perfectly under neg. pressure. The seal mechanism MAY rely on positive pressure. One way to find out.

 

Those look like pretty standard QD fittings. Most of them get their seal from positive pressure. BUT really once you seat the seal with positive pressure the first time they typically dont leak under vac too badly. Course there might be more than meets the eye in the DOT fittings that makes them special, but I doubt it.