Before there were brakes, did people say pull on the reins rather than hit the brakes? Given that buggies had brakes this could easily be an expression from before the automotive. And that's the case. The 17th century is the origin of "hold your horses." Before that Ancient Greeks might have originated the phrase.
Hold your horses Rein it in Slow your horses Cool your heels Cool your jets - oops that one is recent from the 1950s
These seem more recent: Slam on the brakes Hit the brakes Jam on the brake
And the origin of hit the brakes? What do you think of this one?
The origin of this phrase can be ascribed to the men of the underworld of 1850s Detroit. Legend has it that the rate of organized crime at that time was so high that a lot of Mafia factions existed. However, as with all things, there is always an alpha. In this case, it was this really brutal family that didn’t waste any time sending graphic warnings to whoever tried to cross them. They usually ensured that their enemies or whoever disrespected them publicly or privately were executed. They were said to “put the brakes” on these people. The expression caught on and over the years the meaning moved from the really gruesome to the mild as it can now be used to describe stopping someone and not by killing them.
