It's hard to describe but i will appreciate any thoughts on this.

It occurs only when i lightly apply the brakes and is easily produced when traveling under 10mph and touching the brakes. it sometimes happens when i'm making a left turn and braking same time.

The noise is quite literally like a fart coming from the rear of the car. i don't know any other way to describe it. the noise stops when i left off the brakes. If i apply the brakes with significant force there will be no noise, only happens when very light brake pressure is applied.

The car doesn't tremble or shake or anything.

I don't know if this is part of the problem but when driving over rough and uneven pavement, it sounds as if something is bobbing or jumping around in the trunk.

any input? thanks

 

Have you jacked it up and checked out the bearing and the brakes yet? That's likely the quickest and easiest course of action.

 

My guess is gonna be the rotors. My car did the same thing. Sounded like your driving over a storm grate.

 

I have a similar problem but from the front. I dont believe mine is because of rotors though. I am leaning more twards a wheel bearing. I had the same problem in the rear and a wheel bearing/hub relacement fixed it.

 

I had a similar problem. My problem was not because of rotors. My rotors and pads were ok. However, my caliper wasn't it didn't retract which cause the noise on the back. So I had to change the break caliper. If you can, check if the break caliper works properly.