Here's the story, I dropped the engine out of the car a while back and when I did I stripped the flyer on the two front break lines, so I had to cut the metal line. I'm getting the lines replaced tomorrow or the day after, but I'd like to start the engine up in the main time. Is this possible? I don't want brake fluid shooting everywhere, so I figure I can just leave the master brake cylinder unhooked, but I have no idea what could happen if I do that. I also have TCS... Any input?

 

You will not have a problem. As long as you do not push on the brake pedal, brake fluid will be "shooting everywhere"..... there is no pressure in the system unless you press on the brake pedal. Has nothing to do with whether the engine is running.

 

The engine provides vacuum to assist the brakes, but as Injuneer stated, as long as you don't press the brake pedal everything will be fine.

 

Excellent news. Thanks for the help guys.