Loud buzz from rear drivers side

[Haynes]

I have a 99 Silverado 1500 4.8L standard cab manual. Recently, just after making a turn (both left or right) from a stop or slow roll, I sometimes hear a loud, brief buzz on the drivers side somewhere behind me, just a second or two after pressing the accelerator (normal, not hot rodding). It sounds electronic or hydraulic. Has happened in both 1st and 2nd gear. It’s not a vibration, grind, or constant hum. It sounds similar to but much louder than the sound made by new vehicles when you engage the electronic parking brake. It’s hard to tell exactly where it’s coming from, maybe near the fuel tank but not the fuel pump. Everything seems to be working normal and nothing looks broken or out of place underneath. Anyone have any idea what this is?

[sefiroxx]

Not much back there. Brakes, fuel pump or special suspension.

[Haynes]

I haven’t heard it since filling the gas tank. Suppose if I were driving at 1/4 tank its possible the gas sloshed around, the fuel pump didn’t have anything and got loud for a second?

[sefiroxx]

Ok, the fuel tank baffle that is supposed to hold fuel near the pump may be failing. A full tank will keep fuel nearby. So monitor as fuel level drops.