I put my rebuilt brake mc back on my car. I opened the front outlet pressure fitting that goes down to the servo thinking that it would fill the mc by gravity once I filled the rear brake reservoir thats connected to the mc via the banjo fitting. However, the mc didn’t fill up. I eventually shoved the rubber hose from the mighty vac into the front fitting on the mc (see pic).
Wouldn’t the master cylinder be primed by pulling fluid through it? The only other odd thing is that when I loosened the other end of the hard line (see pic yellow circle)
I had the entire brake system: mc, slave, and booster rebuilt in 2014 by white post and got it all working afterwards so I know I am capable of bleeding the brakes, but I can’t seem to remember what I did. Thanks!