Bleeding new brake system without an engine- need to wait?

[msg]

Ive finally completed the install and i wanted to test for leaks and thought to bleed the brakes. I may be premature, does the engine have to be running to do this? Just to test for leaks? I havent installed the engine and was hoping to test for leaks first in the brake system.

I bought the plug for the prop valve and replaced the sensor with it. Ive got a bleeder kit also ready to start, just wasnt sure what I should/shouldnt do next.