Whining Noise - Brakes?

Whining noise associated with brakes. It goes away once i brake or when I accelerate. I only hear it when coasting or for a short time when the truck is in park with the brake pedal released.
I wonder if there’s a leak in the vacuum line from the manifold to the booster which would explain the noise going away when braking and when accelerating right?

Any advice appreciated

 

Rotational squeak?

 

Maybe, but idk if that also covers the whining noise that lasts for a few seconds while it’s stopped and put in park.

 

Can you replicate the squeak when stopped by reving engine?

 

Whining noise goes away when accelerating in motion. The noise lasts a few seconds with engine off and car in park with no pressure on brake pedal.

 

Whistling sounds are generally associated with a failed brake booster or vacuum leak. Whining, would imply a bearing or pully complaining.

However if the noise persists when the truck is off, probably a brake booster.