Brake pedal noise

[Kdubski]

Brake pedal developed a crackling sound some ~300 miles after installing motor in car.

Can reproduce sound each time I press pedal hard, whether in motion or standstill. If I brake lightly then there is no sound. When car is off, sound can be reproduced until brake pedal has pressure (after 2nd pump of pedal).

Really scratching my head on this one as all performance is unaffected but definetly dont want to second guess my brakes.

Video with sound: https://youtu.be/FlRqpdBCTSw

[FBloggs]

It probably needs new upgraded bushings at the pedal hinges.
my clutch pedal sounds like a hoot owl on the occasional application.

[Kdubski]

I can see how bushings would make a sound but this is extremely sudden (no play in pedal) and sounds more like a pressure or vacuum issue. I dont understand how the brake assembly in detail yet so asking for help here.

[FBloggs]

It is possible something got kinked during r&r of the engine, or something developed a crack, or popped loose.