put the brakes on

verb2

1. •
   To stop (an event, action, or process) or to slow it down.

   • "[T]he fight I saw that day made the others look like a young ladies' quadrille. . . . [Y]ou could no more separate them two than you could put the brakes on a blame earthquake." — 1903
2. •
   To cease to perform one's current activity or to decrease one's level of activity.

   • "It would have been so easy for him to have the kids rolling on the floor, doubled up with laughter. So he had to put the brakes on at times." — 1989