Strange Noise while Stopped

I searched the forum and couldn't really find the same type issue. My truck is an 06 trd off road. This issue just started the other day. When stopping at a stop light or waiting to turn with the brake pedal pressed there is a strange noise coming from right around the fire wall are on the drivers side. As soon as I release the brake and start moving or just release the brake and remain stopped the noise goes away. I never hear when braking while driving. It starts after the truck as came to a complete stop.

What could be in mater cylinder area to make this sound? Would it be a vacuum leak? My fuel mileage as decreased some as well but no check engine light.

Thanks
Matt

 

1) It would help to describe the kind of noise that it's making? (popping, clicking, hissing)

2)If it's a vacuum leak outside the master "ie" the hose going to the master, brake pedal should be hard too press to get the truck stopped, ( if you get my description)
If it's inside the diaphram of the brake booster which could be "ripped", "torn", or just have a hole in it, you would only hear it when the brake pedal is pushed

Hope this might give some insite to your problem

 

The best description I could give is like a bad bearing squeal sound. I would say its similar, but louder, to the sound the blower motor makes. I will get a video in the morning. The brake pedal seems to have no different feel then before and brakes fine.

 

Wasn't able to get video this morning. Will try when I get back in town at end of week.

 

If possible, try and reach for the wiring harness under the dash while in drive with the brake pressed. Move it around some and see if it goes away. Sounds silly, but these trucks have a lot of noise coming from them. That's at least how I solved strange sounds from my '06 and '11. Zip ties fixed it right up. Our trucks idle rough at a stop while in drive. You never know. GL.

 

The only thing I can think of ATM would be a hole in the diaphram of the booster, if you can get it to make the noise in neutral or park try stepping on the gas to see if the sound changes