Hydroboost braking systems
There's a serious misconception about what happens if the engine quits. You still have stored pressurized fluid and can get up to 4 applications of the brakes.
No there is (might or might not be) NOT a misconception. The first hydroboost I rode in was in the 80's, a then new Chev wrecker, big block, auto. You put it in neutral, shut off the engine on a 'safe' road. and good luck, either steering OR braking
My cummins is the same way. You kick it into neutral, shut off the key, and you can stop it EMPTY, with little confidence or reserve
I will admit that a light car like an A body might be different.
What I'm saying here, is don't make this sound like the yellow brick road. I've considered these for my car, and decided not needed. My car is apart, but when running I had 4X disc brakes and the original master. Worked great, and my legs are not that strong, anymore.