Hard braking sound

Hello,
Just curious if anybody out there has had an issue with hard braking? Every once in a while, if I have to slow down rapidly, there is almost a grinding sound that I hear. Doesn't happen every time and normal braking is fine. Doesn't really sound like the brakes and I've had the dealer do the transmission flush, the diffs, and recall repair was completed on trans and they haven't mentioned anything about it. Any ideas?

It sounds like you may be hearing your ABS system activating. When the system activates, the HCU pump is commanded on to build pressure. This can sound like a grind or buzz noise.

Hmm, I guess that could be a possibilty! Maybe it just sounds different than the one in my car. I'll keep an eye on it anyway. Thanks!