Experiencing a popping sound when applying the brakes. Seems to be from under my driver seat or between the seat and back driver wheel. It only pops once when I apply the brakes. does not pop when I let off. Popping will go away after driving for a while (or at least seems to).

I searched thru old threads and found some things to check but thought I would ask for suggestions as well. Thanks.

 

Trans mount, bad brakes, loose components? Could be a hundred things and a forum search for "popping brakes" may get you nothing, or a hundred non related items.
Noggin pokin is your friend. Have you actually inspected anything? Placed the rear (since you state sound coming from mid/rear) on stands and moved the wheels?

 

Oh, yeah. Cant find anything obvious. I'll keep looking.