Weird knock sound

[zooka]

So after the the engine is warm and idling if you press the brake and release you can hear a weird knock sound for a few seconds then it disappears. Has anyone else had that?
i seen on the type r forums others have had this.
https://www.civicx.com/forum/threads/possible-knocking-noise.63944/page-10

 

[FredS2000]

If it's a slight pulsing sound, it may be the vacuum pump recovering after applying the brake. I have not heard this in mine.

 

[zooka]

I stopped by the service dept and they said the same, stated it was a very common from the Vacuum recovery. Spot on man.