Bill, an assembly plant is amazing to watch. They produce a car per minute (436 per 8-hr shift), so all operations must be FAST.
They have tank farms (with every liquid in huge silos) away from the plant, and a central vacuum system, with huge evacuation pumps (compressors) and accumulators. The line never stops, so all the equipment is duplicated for immediate changeover in case of failure.
Evacuate means just that. Air has no choice but to come out, and liquid has no choice but to fill perfectly, every time, without wasting a drop.
'Brakes' are only one system. At the same time the brakes are evacuated and filled, so is the air conditioning system the cooling system, windshield washer bottle, and gasoline. They're done in different stations, but in the same Final Area.
Filled brake and cooling systems NEVER have a void or 'bubble' because again, it is evacuated, then immediately filled (in sequence). Then, the line worker removes the fill hoses and installs the caps.
What about the thermostat and heater core shutoff? Evacuate means ALL air is removed simultaneously from the system, so those components never stop the vac. By the way, that's why the radiator hoses have that wire inside, so they don't tear under vacuum.
All the OEM's have done it this same way for over fifty years. If a evac/fill machine goes down or a car's brake system has a leak, the repair area has duplicate machines. That's three brake evacuate & fill machines, three A/C, etc., in each assembly plant. Equipment cost is peanuts compared to line down time.
How about tires? The tire room loads the correct five wheels, machines index and insert stems in each, mounts correct (directional) tires, inflates, and balances, FIVE per minute, every working minute. Tire semi's are dropping loads many times, all day-shift and afternoon-shift. 2,180 per 8-hr day shift, and another 2,180 for the afternoon shift.
M/C's always come 'dry' and are never bench bled at the plant. Every new car must be delivered with a perfect brake system.