Brakes "skip" as I press down. Whats goin on?

Okay ya guys lost me. lol ....but I thank everyone for the input. My plan is this:

When I get back to NYC, Im picking up the car from the auto glass guy...Im gonna pop the MC open see if there is any fluid within eyesight, if so, fill it up with some DOT 3, if not....Ill be driving...very very slowly to the tire shop to have the brakes bled and tires swapped.

View attachment 1715124168
Basically, the dual reservoir splits the system frt & rear. It's the differential valve that moves towards the side that loses pressure & blocks the flow of fluid to the failed half
while simultaneously turning the warning lamp switch on. There is no extra safety without the differential valve, You would have pretty much zero brakes the same as the
single "death drive" master cyl. on there now. The rate of total fluid loss would be delayed slightly, but w/o the valve, it still ain't a good place to be.