slam the brakes on

slam the brake(s) on

1. Literally, to quickly press on a vehicle's brakes to slow down or stop. He slammed the brakes on when he saw the child running into the street. You risk doing your car serious damage if you slam the brake on without shifting down the gears.
2. By extension, to slow down or stop something one is doing. In this usage, the thing being stopped can be stated after "on." We had to slam the brakes on development when we found out the investors were pulling out.
See also: on, slam
Farlex Dictionary of Idioms.

slam the brakes on

to push on a vehicle's brakes suddenly and hard. (The can be replaced by a possessive pronoun.) The driver in front of me slammed her brakes on and I nearly ran into her. Don't slam on your brakes when the road is wet.
See also: brake, on, slam
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • slam (on) the brake(s)
  • slam the brake(s) on
  • jam (on) the brake(s)
  • jam on the brake
  • jam the brake(s) on
  • jam the brakes on
  • brake
  • hit the brakes
  • put on the brakes
  • ease up (on someone or something)
References in periodicals archive
Then they all pull out again, do 60+, next sign, slam the brakes on and same again and again.