zlacker

The switch to hydraulic brakes was a huge improvement, but I'm not sure when that happened.

>>Walter+(OP)
Between 1918 and 1946 mechanical brakes were phased out. By ww2, they were nearly extinct except on the cheapest or older styled cars. I would argue the bigger advance was tires. Even mechanical brakes are plenty to lock your wheels, but tires are the actual road interface, and old ones are amazingly fragile. Vulcanization was not even known at the start of the auto age, and the rubber would tear off in chunks.

>>Jamwin+gk
Vulcanisation was patented in 1844.

If the technique wasn't known until the 1920s, the issue of the patent exhibits extreme prescience on the part of both Charles Goodyear (1800-1860) and the US Patent and Trademark Office.

https://en.wikipedia.org/wiki/Charles_Goodyear

Synthetic rubber wasn't invented until WWII, when natural latex supplies were rendered unavailable due to WWII.

https://en.wikipedia.org/wiki/Synthetic_rubber

>>Jamwin+gk
> mechanical brakes are plenty to lock your wheels

It's not that. It's pretty tricky to get 4 wheel mechanical brakes to put even pressure on the wheels, rather than most of the force going on just one wheel. Mechanical brake linkages are fragile, susceptible to rust, dirt and jamming, and likely need constant tuning.

With hydraulic brakes, it's easy to get even pressure on all the wheels. You can even put a "bias" in that puts more pressure on the front wheels, which makes for more even and controlled braking. Maintenance is minimal, and there are a small number of (protected) moving parts.