If I heard any "grinding" whatsoever, I'd check everything to be sure nothing fell off/broke etc.
have been installed means now and had been installed means past
Most common cause is worn brake pads or linings. Exposed rivets used in manufacturing - or worse - metal-to-metal contact of the brake components are rubbing together when brake pedal is applied....
You should take it back to the shop that replaced them and ask. It's possible that something is hung up somewhere that's causing the noise.
Trap seal lost and foul air invading from drainage.
in internal bays