transition said:

Spiny Norman said:

Jing Joh said:

This seems like a “we’ve always done it this way” kind of statement. Not saying you’re wrong but I feel like a bit of engineering could produce a better system.

Kind-of. It’s been used for so long because those systems are very well sorted and mature. I’m not sure about these days but part of the requirement in Australia was to have a completely manual way of stopping the car With respect to that, hydraulics are best.
That being said I know that Mercedes in the last decade or so have got an additional braking system on top of the manual hydraulic system that when it senses the brake pedal is hit harder & faster than usual it’ll boost the pressure to the brakes.
There was also a rule about steering also being ultimately completely manual, but I think lately that’s been relaxed to allow for steer-by-wire, so no manual steering at all.

one obvious thing re brakes, possibly mentioned earlier, at least of a vehicle(not trailers for the moment) is hydraulic has immunity to electrical failure. And further, of any shared brake system say front and rear can be run separate (for redundancy also), they would be tied together by common electrical system so anything on the system with electric brake could fail together, same of trailer connected.

also hydraulic lines and piston units (masters and slaves) are substantially resistant to moisture and even stained full water immersion of slave units.

overall the complexity is probably lower compared to electric.

much of the calibration of forces applied of hydraulic is done by the driver ‘dynamically’ maybe is the word, and it’s entirely analogue I guess it would be accurate to say, and ‘proportional’ perhaps is the right word.

it’s a very accurate way to sense the stopping force being applied, and control it.

common pipes between two front wheels is quite a good way to reliably balance/equalize pressure on piston slaves, same of across rear wheels, and not sure exactly how pressure is balanced between front and rear, someone might explain that, maybe on common master so is same. I say that because some vehicles have sensor for weight on the back, registers sag, adjusts pressure applied to back(relative to front)

another thing about hydraulic brakes is they are substantially fire resistant, certainly solid metal pipes are, and thick rubber(I guess steel braided like hydraulic hose?) would be somewhat resistant for short periods to high local heat.

There is a physical proportioning valve that usually sends 70% to the front wheel brakes and 30% to the rear wheel brakes.