anyone ever bleed em like this?

I believe in pressure bleeding (nothing to suck in air) or with a pedal, which is obviously hard "by yourself" I DID score a thrift store pneumatic piston designed to manipulate the pedal by air while "you" are under "it."

But I've bought 2 or 3 replacement master cylinder caps, drilled and tapped them for an air fitting, and bled them with air power. THAT works WELL except for my 04 GMC, 4x ABS, which I have yet to get straightened out. The damned ABS module is under the truck.